While there's much to be said in favor of more creative assignments that aren't minor variants of last year's assignments, the author has drawn the wrong conclusion from what happened. 22 cheats out of 108 is big - and the real proportion may have been even higher, given that it seemed like he caught only either blatant cheats or conscience-stricken/less brazen cheats (the latter category from when he acted people to…
Now, I'm not a teacher, and all those caveats. But in my imagination, my approach would be much less time-consuming. I cribbed this from my high school physics teacher. It involves little detective work and no long drawn out confessions.
When cheating is detected, simply send a note to the student with the following: "I'm aware that you cheated on this assignment. You have received a failing grade on it. The next instance of cheating will be referred to the honor board and you will fail the class." Any student who wished to contest the charge would be referred to the honor board immediately. Contest it with people whose job it is to handle this sort of thing. The policy on cheating would be posted at the beginning of class and strictly enforced.
The reason why this is so much more efficient is because the net time spent compared to a non-cheating assignment is probably negative. This is simply because you no longer have to read or grade the papers that are found to be copied. Since there is no conversation to be had with the student, there's also no extra time spent there. The only marginal cost is if a student wishes to appeal your verdict, but I doubt there will be much of that happening since the consequences would almost certainly be more severe.
This also solves the problem of bad ratings. There's no need to play the hard-ass in this situation, which is probably where the rating trouble comes from. Since the interaction is terse and factual, the students won't have much face-time in which to build resentment. You could even put something like, "I know you can complete this class successfully, which is why I'm not referring you to the honor board on the first offense. Please come to the TA's office hours if you're having trouble on your papers in the future. I look forward to working with you and helping you achieve your goals in this class" at the end of the email to put a positive spin on it. (Although the idea of having ratings come from people with whom the professor is in a somewhat adversarial relationship seems like one that could be improved.)
Anyway, I see where this guy is coming from but I'm not sure his is the right decision. Maybe I'm wrong though because as they say I have not walked a mile in his shoes.