I think part of the disconnect with fans is due to Manning's personality. But here is my quick summary:
Coach Clawson came in with a system and proven track record of turning programs around. He earned the right to his two 3-9 seasons based on what he did prior. And he was good at communicating that plan. We also saw all this raw talent that were frosh and soph and we showed patience as a fanbase. We also aren't historically awesome in football so it was easier to be patient. That patience was rewarded in a good 7-6 season and an even more enjoyable 8-5 season that was more difficult due to a more difficult schedule.
I think Manning does have a system he is trying to employ. He just doesn't have the track record we can linger in as we sit on our thumbs and ride out a shitty season (the way we did mostly Clawson's first two awful years that showed some of the worst offensive football I have ever seen). Manning also does a pretty shitty job articulating his strategy. I do think it is easier as a football coach to state, "we want to get faster," without denigrating specific players while basketball is harder. If you say, we want to get more athletic on the perimeter, it is hard for a Wilbekin not to take that personally.
Not to make excuses, but I also think losing both Dinos and John Collins was just a critical blow. Just like Notre Dame losing all their guys to injuries this year. Since they are coming off years of success, it is easier to swallow. I do sit and watch us lose to NC State at home where I thought we played pretty well most of the game (as did State) and think, if John Collins were in this game for 30 minutes, we win by 8 instead of lose by 8. Or if Dinos is in there for 30 minutes, it is a 1 or 2 point game with 1 minute left. I wonder what our record be with one or both. I think we'd be a 20+ win team with Collins and Dinos; a 20-win team with Collins and a 17-win team with Dinos. Because of that, I am willing to give Manning this year.
On the flip side, his system seems to want that KU like team of long athletic players. Next year, he will have those players, albeit almost all of those wing player will be frosh or soph (save Donovan Mitchell). So, I want to see his system work next year. It worked in spades offensively two years ago. But next year they absolutely have to bring it. I have yet to see us play consistent awesome defense in any of Manning 4 years here. I need to see that next year. Manning's track record doesn't indicate that is going to happen. One of problems seem to be intensity. I suppose you can recruit intensity, but 2star guys can play with intensity so that is totally on Manning. He needs to create an atmosphere that is more intense. intensity can be coached. Collins played with intensity, but I fear he brought that with him from high school If Manning can't coach intensity, he is going to have to go.
