Strongly disagree on the "good coach" part. He took over as coach in 2007 after one year as grad assistant. He inherited one of the most loaded DL cupboards Iowa has ever had.
In his first year, he had:
Mitch King (Jr)
Matt Kroul (Jr)
Brian Mattison (Sr)
Ken Iwebema (Sr)
Adrian Clayborn (RS Fr)
Karl Klug (RS Fr)
Christian Ballard (Fr)
Broderick Binns (Fr)
Mike Daniels (Fr)
He did not recruit any of these players. I suppose he should be given credit for the development of those Fr and RS Fr as many were not highly rated, but I get the feeling it was more look. If he was actually skilled in development, why did the 2011 DL look like this:
Binns, Daniels, Steve Bigach, Lebron Daniel, Thomas Nardo, and Joe Forgy.
That does not look like much development going on, combined with weak recruiting by a position coach and a high-level of attrition due to the fact he was a psycho:
https://www.hawkeyenation.com/football/addition-attrition-the-2012-iowa-roster
After Iowa told him to move on, this is what Reese Morgan was working with in 2012:
Dom Alvis, Melvin Spears, Shane DiBona, Darian Cooper, Carl Davis, Mike Hardy, Joe Gaglione, Steve Bigach, Louis Trinca-Pasat
LTP and Carl Davis eventually went on to be NFL players, but LTP told Ferentz he was going to quit after Thanksgiving during this last regular season with Coach Kaczenski:
https://www.thegazette.com/2012/10/11/what-doesnt-kill-you-can-make-you-a-two-gap-iowa-d-lineman
Davis had 2 seasons under Coach Kac, including his RS. He did not start to contribute until Morgan took over
Perhaps Coach Kaczenski knew technique, and perhaps his in-your-face style worked with some. But it is clear his track record is not that of a good coach.