Yeah, I agree as well. Overt condescension, or worse, insults, divide us further from religious people (and anyone in those groups questioning the existence of God), makes us appear overly defensive, and appears to the religious to lend credence to their arguments that we're not truly basing our beliefs on rationality. (Condescension and insults are most frequently used when logical arguments are unavailable or the person speaking is fueled more by emotion than rationality.)
The religious make fun of us incessantly, which I remember hearing and participating in when I was religious. But that works both ways, I think. Among atheists I have no problem with humor in response to the frankly very humorous beliefs that many religions espouse. I've seen many hilarious images on r/atheism at Reddit related to religion, and I enjoy them very much. But when I speak with anyone religious, I try to be diplomatic and helpful. In most cases -- certainly not all --antagonism only hurts us.