Atheism was a very powerful plank in the Communist agenxa of both China and the Soviet Union. It certainly is no more evil then any othre belief if not taken to extreme, but in those cases it was taken to rather viscious extremes. That is the point - extreme application of any sort of religous belief is not so hot, but relatively few people are extremists.
Dawkins and many other atheists are rigorously criticizing the religous communites of the West when in fact much of that is collapsing anyway and the day of a militant Christian Church is long gone. A few dinosaurs remain.