There’s something to be said for leaving a partly filled vacuum be if nothing better is at hand to fill it.
Islamic countries won’t turn into secular liberal democracies without something like an Ataturk figure.
Assad was the closest "multi-culti" secular leader the mid-east had, or will have. The trend now is towards Sunni majority and strict Islamist rule. Assad was an Alawite, and they have a history of being suppressed by Sunni Muslims. Alawaties drink alcohol, don't believe in Sharia, and also have many non-Muslim beliefs, probably borrowed from Christianity.
Whoever in Saudi Arabia or the USA has tried to arrange Assads overthrow will, by default, put Wahabbists in charge. Christians and other minority groups will then be completely wiped out.
That the US Government would be involved in this, willingly or by default, is evil.