Read the article (comes with my NYT subscription), good read and explains why he has stayed. His painful (having to dismiss people who had been loyal and with/to him for years) reorganization after last season was covered but he knew it needed to be done if the "process" was going to be successful. He continues to focus on the athletes and how to enable them to be successful, and he is able to run the program his way at ISU. We are lucky as a fan base to have him and he seems to be dedicated to building our (and especially the ISU athletes) program.
One of the hardest things to do as a leader is fire people. But you absolutely have to do it for the good of the organization (or Process if you like). Your team will have people that don't perform well. They fail to improve, they get stale or complacent, lose their drive, a million reasons why. But you can't sacrifice the entire ship to save one guy; even when it's a friend or long-time relationship. And you can't do their job for them either.
Hopefully going thru this experience will help make CMC a better leader - add a chapter called "clean out the dead wood" to The Process.