THE DEVIL MADE ME DO IT
There's just a little something evil about Check Raising. On the one hand, you're acting shy and as if you don't have a hand, and then you're saying, "No, I was just kidding! And you're so dumb you fell into my trap!" That doesn't win too many friends at the poker table.
MAKING A STATEMENT
The statement of a Check Raise is basically "I have a good hand." But it can also be a bluff that essentially makes the statement, "Don't think you can run over me!"
DON'T HATE ME BECAUSE I'M LUCKY