No, you don't have to be anti-religion to be an atheist. It's just the most-heard point of view.
I've thought it would be interesting to have a group on AN, "the good side of religion". It would probably have to be moderated though, so it didn't fill up with "the bad side of religion".
Often when atheists criticize certain religious points of view, they aren't seeing religion from the inside. They are evaluating it as a nonbeliever, and it would look different to a believer.
I read in Scientific American a while ago an article on the placebo effect. In the case of pray, the placebo effect will never grow a limb back or fight the Black Plague, but it might set a 'true believers' mind to rest and/or reduce their mental stress. This may then have positive flow on effects for mental health and even allow the immune system to go back to normal, and from this fight infection to a better degree.
So, if you truly believe in pray, and if it helps you to become calm, then I think it is a good thing for those who do it.
Personally I never pray. And I don't think it is right or wrong.