I do not agree that Islam is man made.
Allahu Akbar, my friend, you see they are Arabs all of them, but nobody want to ruled by minority, even when relligion is thing that matter.
Even if the Syria was ruled by people with black skin, with people would not like that.
I hope you understand what I want to say.
Second thing, Arabs Muslim didn't forget what Alawi governement (father of bashar asad) did to them in Hama genocde when they killed more than 20 000 civlians.
Many Muslims in Syria believe in God with passion, just like me in Iran, and you can not expect from them to accept secularism.
https://en.wikipedia.org/wiki/1982_Hama_massacre