Let’s be as dispassionate as possible and try to be rational. This is hard to do with what has become a polarizing issue in Australia; Islam.

What would Australia be like with more Muslims and Mosques. The best measure would could have is to look at Islamic majority nations.

Of all nations 20% of recognized nations (35 nations in total) have more that 80% Muslim population, there are a further 21 nations in the range of 20-80% Muslim these nations make up about 22% of the worlds population.

So on that basis one might expect these Islamic nation to make up roughly 22% of the worlds GDP. wrong, not even close.

GDP defined:

Just before we go further I will define GDP in a way more easily understandable to normal people. GDP is gross domestic product, which is the grand total of the valuable products and services a country produces and sells in a given year.  It is a measure of the  productivity of a country. If you think of your own household it is the value of work done by the members of the household.

GDP per capita defined:

GDP per capita is a measure of the GDP divided by the population level, which is an attempt to measure the average productivity of an individual in that country. So If Mum and Dad had two children the GDP per capita for that household would be =  (Mums income  + Dads income)/4. The 4 being the total people in the household. Clearly by this approach the more kids you have (which we assume are not earning any significant money for the household) really drag down the average. But this mean you divide you income between even more people. Because of the large size of families in Islamic countries the GDP get spread very thinly. This is made even worse by the unevenness of the distribution of income (and wealth) with a massive share going to elites.

So lets look at this GDP analysis of Islam majority (80%+) countries.

The Muslim share of world GDP is 6.78% less than a third of what we might expect, all other things being equal.

What is worse is recognizing that the overwhelming majority of this GDP come for the Oil trade the extraction and/or transport of oil.

We know eventually the Oil will run out, and then what will that one fifth of the worlds population do to survive?

Without Oil Islamic majority nations will only have 1.28% of worlds GDP and 22%+ of the mouths to feed.

With oil Islamic countries are under-performing, without Oil, they are absolute economic basket cases.

The only real options would be:

To have wars with other Islamic nations to depopulate and take other resources. (Already happening, has been happening for along time).

Move to the non Islamic west. ( The west has taken as many as it can tolerate, and has not worked out well for many western countries, UK, France, Germany, Sweden

Invade Western countries by stealth ( the current Syrian refugee crisis is an example of this and the above.)

Why?

What are the reasons for the dramatic under achievement economically of many Islamic majority nations?

There are many but here are a few. Note there are just cultural observations, the Koran is the source of many of these problems. Get a copy of the Koran translated and see if you can search for different issues.

Education:

Large families and lack of investment in children’s education.

Compared to the west, Schools are uncommon, universities are rare.

60% of Muslims are illiterate.

It is estimated that half of Arab women are illiterate.

More than half of Muslims don’t know whats written in the Koran because they can’t read, they just believe what someone else has told them, a dangerous level of ignorance.

Because literacy is not common the world is simply a mysterious closed place to many Muslims, who are easily misled by their leaders.

The lack of education is one of the reasons unemployment (and under employment) is so high in Islamic countries.

In the west we talk about computer literacy as being important for business, whereas for more than half of Muslims the written word is a mystery.

Family:

Birth control as idea is shunned and multiple wives are common.

Birth rate is high and large numbers of children in a family is common.

Muslim boys are allowed to run wild in the streets, street battles between boys are common.  Muslim girls are under lock and key almost all the time.

This helps create the mentality of the males as adventurers and conquerors and the women as commodities and spoils of war.

Muslim women who shame their families are often at the very least badly beaten and at worst stoned to death.

Population growth is rapid, and often in paces with very infertile land, oil revenues allow for the continuous import of food.

Oil revenues have made Islamic Oil states a ticking demographic time bomb, once the Oil goes, the state collapses.

It is common in many Islamic countries for half of the population to be under 20 years old.

So no only illiterate by also young and naive as well.

Extreme Xenophobia and limited trade relationships:

Muslims seem to hate outsiders. Whatever form outsiders may take

Ancient family/clan/tribal conflicts are still common, the tension between the two major sects of Islam are still festering after 1400, a  problem which started as a family dispute over the inheritance of the first Muslim, Mohammad.

There is the open hatred or other religions which is well documented in the Koran.

Most other religions in the secular west take the view of other religions as this:

Their belief is not correct but its better for everyone if we all just try to get along, who knows if I am a good role model maybe one day they will convert to my faith.

For the Muslim, they wish to kill or subjugate all other non believers, including atheists, and the only thing ever holding them back is lack of numbers.

One cannot really be successful in a modern economic world without trade, and you can’t trade if you want to kill all your potential Trading partners because they are not exactly the same as you.

Also there is significant problems with the level of dishonesty and fraud generally, but especially towards outsiders,  outsiders often feel they will be likely cheated on business arrangements and there is significant history of this.

Hierarchy:

Most Islamic nations are the result of a military coup, and for many states there have been relatively short lifespans for these revolutions. So each of these states is young ans unstable and because of that have paranoid oppressive leadership. This often gives rise to abuse of office and massive disparity in wealth and income. Many Islamic nations appear to be quite feudal in economic operation with a few despot lords under a tyrant king holding almost all the wealth and power and the rest of the population living under abject poverty.Of course feudalism was abandoned  about 500 years ago by the west for more economically efficient mode of production. This Islamic feudal system means that tyrants are common and money is wasted on the whims of tyrants rather than invested into worthwhile productive businesses. This is an absolute third world mode of operation. Infrastructure spending is only what directly benefits the tyrants and they often see little benefit in a building roads as they travel everywhere by helicopter, for example. The religion itself is equally hierarchical which enforces the same thinking, but only offers the path of being a soldier for a warlord as a path from poverty to wealth. Having such a large pool of poor and ignorant men to fight for you only further enforces the hierarchy’s grip on power. Ironically Arab nations are not very good at wining wars with their neighbors because they are fighting other armed people, they are only ever good and fighting their own unarmed people and that further suppresses any divergent thought.

Women:

Women as previously mentioned are reduced to the status of cattle for Muslims, the reason why so few women are in the ‘Syrian’ migration scam is this: women are in short supply in Islamic countries because of honor killings and the wealthy mean in the ruling factions keep them in harems. Remember if every man wants four wives, there is going to be shortage. In refugee camps (and our detention centers) women are raped by Muslim men because Muslim men think  unchaperoned women are whores, and its OK to rape whores. Its sort of like petty theft, something that can be done to those who transgress the faith. It would be difficult to think of any society that treated women worse than how women are treated under Islam. It is mind boggling how any sane woman could advocate Islam without a gun to her head. Clearly the feminists who support Islam are insane, stupid or simply brainwashed. Female genital mutilation, this is more common in the non Arab Islamic nations but is universally encouraged by Islam. FGM is done specifically to eliminate sexual pleasure for women in an attempt to reduce the chance of infidelity. FGM is also done to make women traumatize and brutalize their prepubescent daughters so they do not trust each other. This betrayal mixed with the removal of the organ ( the clitoris) that might create a alternate mental state (sexual pleasure) means the FGM woman will not likely ever think outside of  the hum drum day-to-day grind of feudal Islam.

Utterly unsustainable:

Once the oil leaves the Muslim world one state after an other will fail. This is because the typical Muslim majority state without oil will consume about 20 times as much as it produces, and typically has nothing but sand to then sell. Many Muslim state are in this position and Syria is simply first to fall victim to this economic and demographic cliff. It is believed that much of Syria’s problems stem from former (and possibly currently) US funded mercenaries going rogue and becoming roving groups of bandits and selling oil when they were able to capture oil facilities. This was a consequence of the tribal warfare proclivity of male Muslims. Clearly is better than being starving peasant, well at least while it lasts.  Worst of all the Koran scoffs at the idea of plowing a field, instead advocating war as a more profitable and honorable activity.

In summary:

So this is why even after having a virtual monopoly on Oil for 40-50 years Islamic nations will see everything they ever knew get swallowed by the ergs in Arabia and north Africa, swallowed by the jungle in Africa and south Asia and covered in rubble in the middle east. This is precisely why Muslims are invading Europe and the west  right now, they know its almost game over. They send their peasant army to vandalize and weaken their new proposed feudal fiefdom, Europe.

Of course its the fault of the west that these Islamic nations failed as states.

Because the typical Muslim is young ignorant, xenophobic and warlike.

Of course Muslims are going to blame outsiders for all of his problems and he will use violence, they know little else.