The reason that I mention this is that his monthly letters remind me of a depressingly common problem that most people have to endure at one point in their lives: the clueless jackass who doesn't know sweet Richard all about anything who can't stop ranting about what a keen-eyed observer of the human condition he is. The problem with him is that nothing he sees seems to ever disprove his theories about the people around him. He can hear Ted hint broadly that none of the women he dates ever meet with his mother's approval and not realize that the reason his marriage fell all to shit is because Mommy helped kick it to bits because he's also the same person who can make hateful noises about how Lizzie isn't supposed to feel sad and empty and wonder why she doesn't feel as if she fits in.
While I have mentioned that his reason for not admitting error is a fear of being proven wrong, there's something else that hampers his ability to see the world properly: his need to not engage with the world. John's idea of heaven is a fortress where he doesn't have to deal with contrary (and therefore wrong) opinions and influences so he can lose himself in his hobbies and never have to think about anything much. Eventually, he'll end up like John Galt would in the real world and die alone and forgotten.