This is really on the coaches. (Yes, high school debate teams have coaches.) This was supposed to build useful skills -- public speaking, research, analysis, formal presentations.
It reminds me of that scene in the "Bad News Bears" where the little league coach realizes the grown-ups pushing the kids to win win win are the bad guys.
In my experience, it was the team captains -- other, older students -- who pushed innovative tactics like spreading, kritiks, and postmodernist approaches. Our adult coaches actively discouraged these strategies in the name of preserving the historical style. In my opinion, the new stuff was much more fun and exciting, and I certainly wouldn't have read any Nietzsche or Baudrillard, etc. as a fourteen-year-old without that motivation. I credit that experience with a great deal of philosophical richness in my life even now; who cares that some sixty-year-old thought we were speaking too fast? It's supposed to be for fun; whatever the kids think is fun is what it should be.
It reminds me of that scene in the "Bad News Bears" where the little league coach realizes the grown-ups pushing the kids to win win win are the bad guys.