I think Jon didn’t give a good honest answer because the blunt statement struck him at his core. He may be aware that TV is dying, but he’s a TV man. That’s his identity. Hearing a statement like that on his TV show kind of put him on the defensive, hence all the jokes attempting to deflect. It felt like someone had kind of hurt his feelings with a criticism that hit too close to home. John may be able to make that criticism himself in a different context, but wasn’t ready for someone else to say it to him.