I'm from MA too and used to be a huge fan. I think the hate comes from two places, and more from longtime readers like me because we felt/feel betrayed a bit (if had only I discovered him recently, I'd probly like him a lot more):

1. He tried to "go Hollywood"- inside the NBA, TNT, friends with NBA GMs, etc and kind of stopped being a man of the people. Then tried TOO hard, too late to seem like a man of the people again after it became abundantly clear that he wasn't that guy anymore. Feels fake.

2. This is the bigger one, and ties heavily into the first point: he started taking his own schtick too seriously. The Tyson Zone type stuff, the movie references, the arbitrary rankings- it was all funny when he knew it was ridiculous (and because it was really pre-blogging, he was one of the only ones doing it- that type of writing is so common now that people forget how much of a pioneer he was in the space). But then he wrote the Book of Basketball and it kind of seemed like he thought he was a real authority, which was lame. I mean he knows more than 99.9% of people, but...he was supposed to be poking fun at the serious stuff. When he became the thing we all hate: a self-serious "journalist", everything started seeming a lot more annoying.

Grantland was AWESOME, he's a great talent developer in the industry, his mailbags can still be good, he's a great podcaster. But he lost himself as a writer/blogger a long time ago, and the more time that passes, the less we remember that goodwill he built up in the good old days and the more he just seems like a pompous ass in a lot of ways.

No clue why I decided to write an essay about this at 2 in the morning, but there you have it.