Even if theism is a failure, it's still superior to atheism

[Jehanne]

Not completely true. There is a LOT of mathematics and early science that was developed under Islamic regimes. The Bayt al Hikma was a center of learning for centuries before its destruction by Mongols (who were also not nearly as uncivilized as the stories say).

The problems arose when the fundamentalists took over. That is what destroyed anything good in Islamic intellectual culture.

Exactly how does that make what I said not true?

Intellectuals flourished in Islam not because of it, but, in spite of it. Early on the caliphs were too busy fighting and consolidating power to worry about the intellectuals in Islam, whom they did not understand anyways. When political and religious consolidation began to solidify under the caliphates, it became time for these people to go, as they were clearly a threat to the religious order.