Because they get players into the league, because of Kirks connections to the NFL, which is what the last several posts have been about.
Kirk can also basically black ball you from the league if you don't stay in line and buy into the program.
Also, a large amount of AA players at Iowa haven't been these huge recruits. Iowa, rightly so, gets credit for developing some very good players from 3-4 star talent or lower. That's why so many guys go there and many of them buy in and benefit.
It's the guys who didn't buy in, and were made examples of by guys like Doyle and BF that really got to see the ugly side of Iowa football.
That doesn't just go away in a year. They will do their best to not be blatant about it, and they will do more to prevent it, but deep down the old school "Team of Everything Else" mantra where you squash any semblance of individuality, drill instructor style, is borderline, and sometimes over the line abusive and unhealthy. Especially for young black men who have been held down by systemic racism their entire lives and can see how the program treats them if they don't do everything they are told.
It goes much deeper than "Doyle was mean so he was fired and now everything is awesome". Please tell me you understand that. I think you are blinded by your allegiance to Iowa.
By the way, if something like this happened under Matt Campbell I would be 100% for harsh actions to be taken. This kind of **** just shouldn't happen in sports anymore. Call me "woke" if you want, but regimes that still push this covert racism BS need to be cracked down on and ended.