fsk8r, I think it's a little more complicated than that.
Especially for students new to a sport, who would often want to shop around, or try other coaches. The PSA rules were used by many coaches to stop that.
In addition, for many skaters and parents, lessons cost a lot. A few cut rate coaches could take a lot of the students away from many coaches.
Picture Google ads aimed at people in a particular geographic area who search for something with the word "Skating", advertising someone barely able to teach skating; a student or parent fairly new to the sport, might not know how to distinguish that.
Likewise very good teachers can now easily poach. Many, perhaps most, relatively inexperienced students and parents don't recognize the differences are all that great, but with a free lesson offer, they could find that out easily.
Both of those will sometimes be great for students (except perhaps when they get a poor teacher and don't realize it), not so great for their current teachers.
As a slightly similar example, among academic tutors in my geographic area, it used to be that you could get easily $45 to 80 / hour in most subjects. But a few websites that made it easy to shop around has brought it down to more or less minimum wage (because other students have flooded the market), and many tutors are having economic problems.
Another example: I was taking kayak lessons from one well respected instructor. I was reasonably happy with him. Then another kayak instructor aggressively recruited students (which has always been legit in most sports), pointing out he'd been to the Olympics. I tried him out. He turned out to be a much better teacher for me (he was very good at analyzing problems, and at explaining them), even though I didn't need an Olympic caliber coach by any criteria, and to a large extant I switched. In fact, he took over the lion's share of the local kayak instructing market. Again - good for the student, not so good for the original teacher. (The new instructor was much better at teaching than at making a living at it - he underpriced most of the other teachers, including my former instructor, and closed local shop with debts after a few years.)
Another possibility is for opportunistic students to take advantage of many coaches who each offer one free lesson, instead of paying for lessons.
The PSA exists in significant part to make it possible for coaches to make a good living (which is an anti-competitive goal). Of course, they still have requirements coaches must meet, if they are to get PSA or USFSA or ISI insurance, which is required by most U.S. rinks. That is different from the tutoring market. Nonetheless, except for cut rate or truly outstanding coaches, the rule change could easily hurt the income potential of typical coaches.