The simple fact is that if you raise a devout Muslim in a middle-class American family he or she probably has no more a chance of turning into a radical than a devout Christian. Let alone a merely 'practicing' member of either faith. This suggests that the faith itself is basically irrelevant and the conditions are what matter. The only reason we get more radicals out of Islam is because Islam occupies portions of the globe where conditions are comparatively bad.
Kosh's last argument against this assertion was two-part.
First, he asserted that Islam insinuates itself into political structures, perpetuating the issue. Yet it is apparent that other religions can do so as well. Clearly, we cannot predict that Islam is somehow particularly virulent in this respect due to some trait of its tenets and doctrine rather than due to the environment it exists in. (Kosh would have a fair argument if, like NGTM-1R, he had pursued the issue of sharia law, which is specifically problematic; yet sharia law is not widely obeyed by Muslim citizens in First World countries, suggesting it too is an environmental factor.)
Second, he asserted that the kerfuffle over political cartoons was evidence against this. Yet that outrage occurred primarily amongst recent immigrants and in Muslim countries in poor circumstances.
None of these arguments can address the fact that there are vast, stable, non-radical populations of Muslims who are as healthy and calm as any Christian, Buddhist, or Atheist. And that statistically inassailable fact means that we cannot assign blame to the tenets of Islam as a faith rather than to the conditions in which Islam exists.
If we wrote an alternate history novel (as Iain Banks once did) in which Islam was the religion of the modern world and Rastafarianism the religion of the Third World, we would see alternate-Kosh posting a thread on alternate-HLP about how Rastafarianism has no place in this century, given the virulent outbreaks of homicidal reefer madness currently devouring the globe. It would, of course, ignore all the happy Jamaicans and what-nots going about their lives in peace.
Singling out a single religion as one that 'does not belong in the century' is a claim that requires extraordinary proof. It requires proof that the religion on its own, taken separately from geopolitical factors conflated with the analysis, breeds intolerance. Kosh has made this claim: he endorsed the simple equation "Islam = intolerance." He has been so far unable to substantiate this claim.
Making such a claim about religion in general would be more defensible, but even then, probably incorrect; ingroup like and outgroup dislike is a fundamental trait of human psychology, and it has always, ALWAYS been exacerbated by issues of resource distribution.
I do think it's important to recognize one point in Kosh's favor: that poverty and bad education alone are not what makes a terrorist; many are middle-class, well-educated, and motivated by religious philosophy they picked up online or from friends. But the fundamental systems that establish this cycle of religious radicalization are not driven by tenets of the faith itself; rather they are rooted in the geopolitical realities of an entire band of the world which was essentially pieced together, Frankenstein-style, from colonial remnants while undergoing a massive post-colonial backlash. We have no way of knowing if Islam is peculiarly prone to radicalization (which is the claim being made here.)