These people should visit atheist blogs -- like FreeThoughtBlogs or even my own humble blog, and check out the happiness level. We're wildly happy. We love our lives. And by the way, we're the smart, funny ones -- as opposed to the humorless dolts who believe in gods. (And we get satire while it goes right over their heads. Just saying.)
Nothing to live for?! The universe is startlingly beautiful. And, without the help of gods, scientists have been learning more and more about how the universe works. The discoveries are endless and awe-inspiring. Reality is much more beautiful and complex than a silly religious story. God is a tiny idea, a paltry idea, when compared to the glory of reality. Religious people should drink some espresso and read a few science books. (Oh, I forgot, they can't. Reading anything other than the bible makes their heads hurt.)
Religion teaches people nothing about reality. It's just a scam, a dreary list of tiresome, meaningless legends. I guarantee you that if you study theology for the rest of your life, you will learn absolutely nothing.
Unhappy atheists? Anyone who says that is wearing blinders. Wake up! There are no gods. And life is great! (Hopefully you read that last line with the proper Tony-the-Tiger voice.)