I worry about the San Francisco 49ers this season. Jim Harbaugh, who was not welcomed back by the 49ers and went to the University of Michigan after last season, pushed that San Francisco team hard. Here’s what San Francisco guard Alex Boone had to say about it, on HBO’s “Real Sports.” “He does a great job of giving you that spark, that initial boom,” Boone said, via Pro Football Talk . “But after a while, you just want to kick his (behind) … 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. “I think he just pushed guys too far,” Boone said. “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.’” It’s not a bad thing that Harbaugh was demanding. He came to a team that hadn’t been to the playoffs in eight consecutive seasons. His first three seasons they made the NFC championship game, winning once. Was he a tough coach? I’m sure he was. You know what else Harbaugh was? Extremely successful. Boone knew this. He said so last September. “So what’s the problem? I’m confused. Is winning not good? Is business not a’booming right now, boys? ” Boone told 95.7 The Game last September, via CSN Bay Area , when asked