People are allowed to be blunt and even curmudgeon, there's nothing wrong with that, it's just one of the many dispositions we can assume. That's diversity. This is a personal blog and it's totally reasonable the he takes this posture, it's slightly refreshing. If this were a public intellectual being taken seriously, or if he had a huge audience, then there would be more scrutiny, but otherwise he's just a guy with an odd way of communicating with a small soap-box on a small corner. It's fine.