The mongols sacked Baghdad, killed everyone, and destroyed all institutions of higher learning and the people working in them. Then the age of exploration permanently shifted the center of world power away from the Middle East and the Silk Road. Then European colonial powers subjugated those territories. Afterward, Saudi Arabia started exporting its very "particular" (to put it lightly) branch of Islam. Sprinkle some US intervention and you get to the present day.

Not much of a turning away, but a systematic and violent dismantling of institutions of learning (and a supporting culture) that took centuries to build. No surprise that those conditions didn't happen again in the same place. In most places, such a golden age never happens.