Because evolution is evil.
BZZZZZZT. Wrong. Could it be because creationism is filled with nothing but nattering nabobs of negativity, with no scientific program to speak of, yet willing to resort to bad logic to keep the money rolling in?
I really do want to see that Penn and Teller special on Creationism that is coming up on Showtime this week. I suspect it will concentrate on the similarities of the creationist preachers that go from church to church to the folks who want to sell you a bridge in Brooklyn...cheap.