It is not enough for a team member to be fantastic in a solo role. I'd be more interested in hearing from other faculty than I would from the students, who don't much experience actually working with Coward.
And in any case, if someone on a dev team got significantly better numbers by bucking the trends, I would be obligated to try and understand their methods and help them gain greater acceptance. It doesn't make sense to remove someone who gets results. It makes sense to integrate them.
Did that turn out bad for the team? Not really. Life goes on. And sometimes its just a good learning experience for both parties.
I taught math as an adjunct at a Big Ten university with a prestigious math department several years ago. I never once met with any member of the faculty, even my supervisor, and nobody ever observed my teaching. All of the sections of the course that I taught had the same syllabus and exams. I had students from other sections sitting in on my lectures.
As for hearing from faculty, oddly enough I was on the other side of the issue as well, since I also taught the 3rd year "weeder" course in electrical engineering. My students were woefully unprepared in math despite N semesters of calculus in the math department. Once during a break in the activity, I asked my engineering students how the university could improve engineering education. Their consensus: Better math teaching.
Yes, there could still be confounding factors. He is seen as an enjoyable lecturer, and students who care about their classes enough to select the better lecturer might be better students. But still.
If you want to continue the analogy to software engineering, the modules he's producing are students, and they are meeting their specifications (later performance) quite well.
The closer comparison would be a Big 4 accounting partner (or law firm partner) that bring in revenue, is well loved by his clients. You know what would happen if the firm fires them? The clients leave with the partner. Luckily for Berkeley their clients can't leave nilly wily here.
Edit: On second reading, this was mentioned: "Further, the current Interim Chair, Craig Evans, explained that I am causing problems because students are not signing up for other Professors' classes on account of me. This is to be observed this semester, Fall 2015."
Yeah, if this was some consulting professional firm, the firm would be in big trouble already.
Perhaps it's the other professors who are causing the problem by not putting any effort into teaching well?
Mathematics is actually fascinating, but teaching and listening to math lectures is generally not interesting at all. Anyone who can teach it and keep Students interested and have them understand the material is a gem and should be kept at all costs!