He did have success. In fact Johns super bowl ring came at Jims expense.
But he was not lighting it up during the UM opening period. I remember a majority saying he was leaving, one way or another.
Edit: just went and checked the numbers. He went 12-4 during his 2012 super bowl year. In his 2014 final year he went 8-8. In 2015 after he left SF went 5-11. Jim skeedaddled to UM while the chance was there. But not sure I would blame him. He probably had more success than Saban and Saban skeedaddled too. And it turned out just fine for him.
I think your perspective on Harbaugh's tenure in the NFL is a little askew...as is your attempt to think that Michigan is no better off than we are at UT....
The 49ers were 46-82 in the 8 years before Harbaugh's arrival. He went 44-19 in his 4 years at the helm....
He went 13-3 and lost the NFC championship in his 1st year to the SB champ NY Giants...
He went 11-4-1 lost the SB in his 2nd year to his brother's Ravens...
He went 12-4 and lost the NFC championship in his 3rd year to the SB champ Seattle Seahawks...
He finished his 4th year at 8-8 when his defense was 5th best and his offense rated as 30th....mainly because of a poor OL and poor QB play...
The 49ers are 7-32 since his departure....
Additionally--
He rebuilt Stanford from the ashes of a program in the PAC-12 over his 4 years there and was 1 game away from playing Auburn for the NC after the 2010 season.
He has led Michigan to a 25-8 record and is 15-6 in the Big 10 since taking over...
And he is 127-54-1 overall as a Head Coach which gives him a winning % right at 70%....
IF you are even remotely attempting to say that Michigan is no better off with Harbaugh than we are with CBJ--it just defies any sense of propriety....
CBJ couldn't be Harbaugh's waterboy......
Harbaugh had to replace 18 starters from last year's Michigan team...and has over 15 Freshman in his current 2 deep....and still beat the sheet out of Florida...TWICE at Michigan...outscoring them by a 74-24 margin in 2 games....a team CBJ has gone 1-4 against....