You wrote no about the large number of bowl games defining for you what makes a successful coach, but then went on to explain how a bowl helps with PR, and how a bowl gives more practice time, and how a bowl helps with recruiting. Then you wrote about all of these coaches who took their teams to bowl games. And to top it off, recruiting could tank, the team get blown out in seven games by 40 points or more (which means losing more games than they won), yet, you would retain Lovie since he led the team to a bowl game. You wrote no, but I'm pretty sure you meant yes.No. Winning football games defines what makes a successful coach. Not eye tests. Not moral victories because we only gave up 63 points once instead of 3 times. Not subjective statements like "well they were competitive for a half in most of their games"
Winning as many games as you lose is the barest of bare minimums in this case. That means 6 wins and that means a bowl. Which means better PR for the program than sitting at home. Which means more practices with which you can help drive more learning, more instruction, and better preparation for the following year. Which mean you can tell recruits you went to a bowl game. And if you can't get to a bowl game by year 4, then you aren't a successful coach.
And, coaches that are obviously better than Lovie Smith can accomplish this minimal feat well within 5 years elsewhere.
Brohm takes Purdue Bowl games in years 1 and 2
Campbell takes Iowa State to bowl games in years 2 and 3
Mendenhall takes Virginia to bowl games in years 2 an 3
Babers takes Syracuse to a bowl game and 10 wins in year 3
Leach took WSU to a bowl game in year 2
All of those programs were in as bad of shape or worse than Illinois. They made good hires, and those good hires won on the field. They aren't still looking for people to make rationalizations like "Well, we only allowed 2 games of 50+ points this year, so that's good enough for me" in year 4.