This is like saying a smoker can't criticize the tobacco industry. It's entirely possible to recognize that AI in school is a huge problem while (hypothetically, in this case) still using it. Indeed, if enough of your peers are using it and you do not, you are effectively being punished for being virtuous. It's a lot like being the one cyclist in the Tour de France who isn't doping.
Similarly, if your peers aren't able to keep a conversation going in a seminar because they had AI do their reading and assignments for them, then you, as a student, are having your education stolen from you in a very real way. Education is something that happens in community. When enough of your community is using AI, your education will suffer.