>>8Let's make up some conspiracy theories.
Errr, let's see. Since Islam was an impossibly strict religion with numerous taboos to begin with, it's possible that the leaders deliberately impose strong restrictions on things that may nurture intelligence on political wars and rhetoric (yes, for example, chess).
Furthermore, it also serves as a mean to eliminate recreation, and no recreation = high cognitive load, so the people are too tired to consider anything unnecessary, like, for example, doubting the leaders' words. And now they have a slew of devout followers that follow their every word to the letter.
Was that a good theory?