9. Prolonged public exposure will bring back "the rash."
8. Will give rival Carbolic Smoke Ball blog material for months.
7. He could wear that "awkward hybrid of football jersey tucked neatly into pressed suit pants" again.
6. Might lose O'Connor's Playbook in the Big Apple.
5. Not allowed to appear on the show without an escort by members of Act 47 Recovery Team and Oversight Board.
4. Gives the media one more chance to make cliched baby-face/old steel town comparison.
3. Dogs from prior Stupid Pet Trick segment will sniff embarrassingly at his pants hoping to get at the chipped ham & Heinz ketchup sandwich he's tucked in his pocket as a gift for Dave.
2. Hasn't Pittsburgh suffered enough?
And, the number one reason why Luke Ravenstahl should not appear on "Late Show with David Letterman":
1. Like, dude, you'll look like some old geezer compared to the novelty 18 year-old mayors Dave usually has on in that slot!
(h/t to pittgirl where I first heard about this.)