I don’t comment much on religion. However, I don’t see anything inherently wrong with such criticism. Daz addressed the topic in his recent post “For People Who Don’t Believe In God, You Atheists Sure Do Talk About Him A Lot” and I think he made his point very clearly and succinctly.
I particularly liked his final line:
I certainly respect your right to your private belief. And when that belief truly is private, I’ll shut up.
I recommend that you read his entire post.