Bashar el-Assad is, like his father before him, a despot and a killer prepared to do anything to retain his grip on power. But he does have some things going for him ... he is secular and allows freedom of religion (of a sort) and promotes female equality (perhaps due in part to the influence of his British wife)
The huge danger for the West in trying to engineer his downfall is simply ... who for they replace him with? You might argue that is for the Syrian people to decide. Oh that was so simple ... it's not. The Free Syrian Army formed in 2011 by defecting Syrian Army personnel was generally seen as a providing a centrist alternative to the Assad regime. At the very best it was a disparate grouping and in recent years its influence has declined to the point where it is now a bit player to ISIL, the dominant force, who are committed to the establishment of an Islamic State with all that implies.
The Assad regime is supported by Russia who, while perhaps despairing at some of the goings on of Bashar regime are comforted by the fact that, while he is a bastard, he is at least 'their bastard'. Their support has allowed them to establish and maintain a military presence in the area. They will not want to relinquish that.
Syria looks like becoming a proxy for the USA vs Russia. There is a small common ground. Both are committed to the destruction of ISIL. Beyond that not much. Russia is committed to supporting Assad. For the West and the question has to be ... what's the game plan should 'they' succeed in toppling the brute. There are lessons to be learned from Iraq. You leave a vacuum and that's the recipe for mayhem. I hope they have been learned well.
Damned if you do and damned if you don't perhaps!!!!!!!!