I thought there were two things that really impressed me about what a nasty Letterman was.
The first was indirect, in that he was nasty to Shirley MacLaine, apparently for no particular reason, and so when she told other actresses that he had a “bad aura”, or the equivalent spiritualist babble, they went on his show expecting the worst, and were not surprised when he mistreated them as well. And then told him to his face that they came on his show while knowing he was a creep, so weren’t shocked by his rudeness.
The second was more to the point, that Letterman does not like animals, though he had to invite them on the show, and the animals picked up on that dislike and returned it.
Maybe she had a point about his “bad aura”, but that’s pretty obvious with a jerk and a-hole like him.
I don’t trust anybody who doesn’t like animals.
I remember Carson used to have that lady from the San Diego Zoo on. She’d bring in all kinds of exotic critters, and Carson would let them crawl all over him, pee on him, etc. It was always a funny bit.