I've listened to the show for years. I think that Howard is simply in a much happier place in his life, which may not be condusive to being "relevent." He's been in three-times-a-week therapy for years (making him a much calmer, happier guy), signed a contract for $500 million and just married a super model. Yeah, that's irrelevent, for sure.
When I tune in it's just to hear old friends do their thing. I don't care if "A" listers don't come on - give me Eric the Midget anyday.