It's just the sheer myopia of it. The assumption that, just because his life sucks, EVERYONE'S life must suck. And if anyone else's life DOESN'T suck, which completely invalidates his world view, he makes it suck.

It's like, yeah, everyone's life sucks, because of people like you. If you just stopped being like you, everyone's life wouldn't suck.

I mean, in this episode, he's literally like, "Don't worry, in the new world I create, you'll all be together." They'd have been together NOW if you hadn't made sure one of them died! You aren't fixing the world anymore, you're fixing your OWN evil fucking deeds! Which you wouldn't have to do if you just DIDN'T DO THEM IN THE FIRST PLACE!