> I'm not sure why exactly the pendulum swung so hard to conservative side
In Afghanistan, because in the wake of the Soviet takeover, the US (and Pakistan and some others) threw lots of money into funding religious extremists to fight the Communists, which was eventually successful, at least to the extent of forcing out the Soviets and establishing something like control by the religious extremists of much of the country (though competing warlords were still a factor.)
To a certain extent, similar factors are present in the Middle East (at least to the extent of religious extremism being a product of forces that were backed by superpowers for geopolitical reasons during the Cold War.)
In Afghanistan, because in the wake of the Soviet takeover, the US (and Pakistan and some others) threw lots of money into funding religious extremists to fight the Communists, which was eventually successful, at least to the extent of forcing out the Soviets and establishing something like control by the religious extremists of much of the country (though competing warlords were still a factor.)
To a certain extent, similar factors are present in the Middle East (at least to the extent of religious extremism being a product of forces that were backed by superpowers for geopolitical reasons during the Cold War.)