I'm an atheist. I often criticize believers for their beliefs. And I'm not going for any of this "religion is the belief not the believers" bullshit. That's one of the appalling pieces of non-thought popularized lately by Sam Harris. I don't know whether he thought it up on his own or borrowed it from some other idiot. However it happened, many atheists are using it as an excuse for rude behavior.
I'm not saying that people should never be rude. There's a time and place for a very wide range of expression, in my opinion. But I own up to what I say. When I say nasty things, I don't claim afterwards that I wasn't being nasty, because "I was talking about people's beliefs, not the people themselves." Sorry, I call bullshit, you can't hit one and leave the other unscathed. Can't be done. I often say "God doesn't exist" and "religious belief is ridiculous in this day and age" and similar things. And I don't try to deny the feelings I'm hurting when I say such things, or say that those feelings somehow don't count. I say them when I think it's important enough to hurt people's feelings. Which is often, because people's rights are at stake because of other people's beliefs, and also just because it's important to speak the truth, and because I don't take for granted that the freedom to speak openly will stay around for ever. We're going to have to fight for that right if we want to keep it, same as with other rights.
But I never claim I'm not offending anyone. That's just weak. And in some atheist communities, it's the weak-ass excuse for some of the most appalling expressions of bigotry I've ever seen. Like calling Arabs donkey-fuckers and then saying, "Hey, I'm just attacking the beliefs, I'm not attacking any actual people." When I say that those atheists are appalling bigots, I'm not criticizing their beliefs. I'm criticizing the actual idiotic atheists themselves, as people.