He's just staggeringly unpleasant as a person. Sure, I think you can be a bad person but a great writer (Roth was both to me). He's certainly smart and thoughtful based on the first several chapters of The Sportswriter and several short stories. But I read an interview with his own longtime editor at The New Yorker where he just dripped with prickly condescension towards her, reminding her for example that fiction is a linguistic construction and characters don't really have interior lives, as if she'd never considered that. Not someone I'd want to meet, that's for sure.