Earlier quoted context omitted.
> At the very least that data does not really fit the theory. What theory? It certainly fits a theory: that insecurity (and, thus, plenty of downward mobility), limited upward mobility, and a steep drop to the bottom combine to provide a condition in which members of the middle class become more prone to reject the existing social order and adopt extreme alternatives that are offered.
You see, that's precisely what's twisting the facts to fit the theory is like. If you have a theory that it's all because of income inequality, and then the facts are that it's not the poor who are terrorists, now you have to amend your theory that it's actually the moderately rich who are afraid of becoming poor. And that's why they go on suicide terrorist attacks?! If it was the poor who did the attacks then it wou…
The insecurities of the middle class and the direction they push hardest being a key factor in both revolutionary violence and support for tyrannical government (depending on whether the fear of the continuation of the current or the fear of its collapse dominates, which can vary for different members of the same middle class) isn't exactly a novel theory, even outside the specific case of middle eastern terrorism (in fact, the first time I seem to remember it is in the context of the 19th Century European revolutions.)
> If you have a theory that it's all because of income inequality, and then the facts are that it's not the poor who are terrorists, now you have to amend your theory
No, you don't, because the theory that "income inequality" is a contributing factor does not imply that the actors are "the poor".
If you have a theory that their own poverty is the reason that individual terrorists become terrorists, you'd have to revise the theory, but that's not what the theory was to start with.
> that it's actually the moderately rich who are afraid of becoming poor. And that's why they go on suicide terrorist attacks?!
No, that economic insecurity combined with lack of upward mobility in the middle class leads to disillusionment with the existing order, desperation, and susceptibility to alternative worldviews to those supporting the existing order.
Now, where on top of the economic conditions, you also have a situation where, due to a variety of factors (including attempts to repress alternative views to preserve the power and privilege of the existing elites) there aren't non-violent, non-radical groups that provide something that feels like a plausible alternative, those susceptible to alternative views are going to be, more than in other circumstances, drawn to violent, radical groups.
> I'm sorry if I sound disparaging, but I've had this debate 50 times before, and the mental gymnastics to keep an incorrect theory alive are virtually impossible to penetrate to the point that I'm not even sure if there are any conceivable facts that would falsify that theory in the minds of those who believe in it.
Facts that would falsify a theory of economic inequality contributing to terrorism would be statistics showing that, controlling for other factors that demonstrably contribute to terrorism, economic inequality has no correlation, or a negative correlation, to terrorism.
The things you offer are facts that would falsify particular models of how economic inequality contributes to terrorism, but those particular models seem to be strawmen.