Harbinger_ said:
I've seen Atheists act this way about Christians and nobody usually cares. Why should this matter?
Because there is no inherent hypocrisy the other way around.
If you are an atheist and you say we should kill all Christians, you haven't violated any fundamental tenant of atheism by saying we should kill all Christians. (Now, you certainly are probably a bad person, but atheism does not profess any sort of moral decrees, it is simply the expression that there is no deity.)
However, if you are a Christian who says we should kill all atheists, you've violated fundamental tenants of your religion. The Christian religion states that one person shall not kill another person, it states that if you feel someone wrongs you, that you should turn the other cheek, it states that no man may stand in judgement of another person's actions, for judgement is the domain of God alone.