He's a murderous freaking tyrant whose actions against peaceful protesters led to this whole mess in the first place, so yes.
But there's no reason to think that his replacement would be 'better'. (aside from the fact its none of our business).
It'd be quite hard to be worse at this point, really. Especially since I suspect that a large portion of Syrians will be weary of fighting and know that slaughtering their own people AFTER Assad is toppled will just lead to more fighting.
A large portion of Syrians are already weary of fighting. It's that portion of those who aren't you have to worry about.