I'm not a fan of Harbaugh (plenty of history there as to why) but I don't know why anyone would hate on Jackson himself. He's not the one saying he's as elusive as Barry Sanders that's all the morons making commentary. He's not the one saying he's changed the game of football that's his coach.
No one is hating the individual. I hate his style because it is not sustainable. Either he'll get injured or the gimmick won't work anymore... just like with the wildcat. He is not good enough of a passer to be efficient for more than 2 or 3 years.