Well, for one, because they grow up to be people that hold stances like this:
"We don't have to protect the environment, the Second Coming is at hand." --James Watt, Secretary of the Interior under Reagan
And mentalities like that harm everyone, especially when a joker like that manages to get into a position of power, riding on the votes of people like you.
Also:
People are not equivalent to their beliefs. If someone thinks their beliefs are absurd, they should have every right to say so. And it's not like most Christians aren't aware of that--they'd quickly mock Scientology or Sun Myung Moon's religion, but out comes the persecution card if someone says anything negative about Christian beliefs.
The beliefs themselves have had a free ride for far too long, and they deserve no more automatic respect than any other baseless idea (and to restate, denouncing or ridiculing a religion is not equivalent to ridiculing the entire body of its members--atheists especially tend to know that most people are indoctrinated into this religion or that while they're too young to do or say anything about it, and most people can't recover from that). Let's try and keep the standards down to one, yes?
Why do you equate disagreeing with a religion with such an exaggerated level of arrogance? Do I detect a tone of "how dare you not agree" in there?
But he's the one not gambling his life away in hopes of hitting the ethereal jackpot. Perhaps it is you who is scared. So scared of death that you have to invent an afterlife just to reassure yourself. Ever consider that?
I wonder why you are so mad at Zeus. Why do you hate him so? Clearly, the only reason one would not devoutly worship him would be anger, right? So what do you think he has done to anger you?
People can't hate entities they don't believe in, goofball. Atheists don't hate God any more than Christians hate Ra.