Why is this site so funny!?

My friend Kate featured My Life is Average on her status message.  I went to read the stories and couldn't stop laughing.

I understand why average stories are so much better than "my life is great" stories.  Who wants to hear about how great someone's life is unless you happen to care about that person?

But I'm not sure why average stories are so much funnier than "my life sucks" stories. That doesn't make much sense to me, but there it is.