I love David Letterman...as a comic

As a culture commentator, not so much.  Don Surber: "Letterman defends Colbert—poorly - In an NYT interview, Santa David made a case that failed like a Colbert monologue."

Colbert was done in by his hubris, which led him into believing he could survive on network television with only half the potential audience.

Oh, Colbert can. He made $15 million a year doing a half-assed job, but CBS made less than zero on the show—reportedly taking a $40 million loss each year.

Don’t cry for Stephen Colbert. Victimhood is a badge of honor on the left and the money will roll in from stand-up tours, TV specials and maybe a movie.

When you strip away all the niceties, Colbert is a failure.  He strayed from comedy for a nightly ego stroke and people changed the channel.  David Letterman - who I saw live in NY during his heyday - should know the difference.