Letterman just needs to leave. Go now. His time is over. He isn’t funny, he isn’t entertaining.
Just go, Dave. Don’t apologize, don’t explain. Nobody cares.
Time to leave.
That says it all. He himself admitted to cheap jokes just to get a laugh. And who's laughing? No one except the truly stupid people who sit in his audience.
Apparently Letterman is so full of himself that he could not admit to making a mistake.
He didn't offer a sincere apology; he chose to try to weasel out of his disgusting comment.