49ers' Alex Boone: Jim Harbaugh wore out his welcome, 'pushed guys too far'

San Francisco 49ers guard Alex Boone confirms in an upcoming interview with HBO Real Sports what we already knew: Nobody likes Jim Harbaugh.

"He does a great job of giving you that spark, that initial boom," Boone tells Andrea Kremer, according to ProFootballTalk. "But after a while, you just want to kick his ass. ... He just keeps pushing you, and you're like, 'Dude, we got over the mountain. Stop. Let go.' He kind of wore out his welcome."

It's not a surprise that the notoriously grating personality of Harbaugh clashed with 49ers players, but Boone goes on to question Harbaugh's sanity - a sentiment that's been kicked around in the past, particularly in an ESPN profile from last year.

"I think he just pushed guys too far. He wanted too much, demanded too much, expected too much. You know, 'We gotta go out and do this. We gotta go out and do this. We gotta go out and do this.' And you'd be like, 'This guy might be clinically insane. He's crazy.' ... I think that if you're stuck in your ways enough, eventually people are just going to say, 'Listen, we just can't work with this.'"

Harbaugh seems to relish being characterized as "insane." He chalks it up to hyper-competitiveness and a willingness to do whatever it takes to win.

He's already putting his abrasive stamp on Michigan, cursing in spring practice, telling his team to "huddle the fuck up," and telling one player in particular "I'm just telling you the right way to do it. If you want to look at me with that look, go fucking someplace else."