I don't think that's necessarily true. Harbaugh could very well leverage scUM for a raise. He's done in SF, but he's still under contract, and having scUM as leverage could help him in getting a better contract with his next employer. Everybody at scUM is conveniently forgetting he is under contract through next year. He's not leaving the NFL. SF will negotiate an extension and trade him before they let him walk for nothing. Some NFL team, be it the Jets, Chicago, Oakland, or Miami will give him GM power in addition to his coaching duties. With his track record, every NFL team with a vacancy will throw buckets of money that scUM cannot match at him. Plus, do you really think a competitive guy like Harbaugh is bailing on the NFL without his Super Bowl Ring after coming so close? After his own brother won one? Come on. No way he passes that up to go back to college and spend his days travelling around the country recruiting 16-18 year old kids.
It's a pipe dream that's being fueled by guys like Webb and Beaver. Besides that, why do scUM fans feel he has some sense of obligation to m*ch*g*n? He's had very public spats with them, and I've never heard him saying anything at all about m*ch*g*n. Ain't happening.