There are debate formats and tournaments that encourage 'actual, useful rhetoric'. I.e. Congressional Debate, Parliamentary Debate, and certain tournaments and competitive circuits in LD. I.e TOC bidding tournaments are oriented towards the high speed fun stuff with Nietzche and Kritiks etc etc compared to the National Debate Tournament which ruthlessly enforces a much more traditional style of debate... https://www.youtube.com/watch?v=LFFOLNdSOWE

High School Debate is not some monolithic top down hierachy- there is a vast array of tournaments and events that cater primarily to the needs and preferences of the students who choose to compete in them for fun.

Fast debate with competent judges doesn't just stop being debate...everyone starts slow and over time learns to speak cogently at speed. If their arguments don't make sense at speed to the judge they are typically discarded outright. Fast debate really opens the competitive landscape, since you have a lot more time to open up complex ethical frameworks and longer arguments. If you and the judge and the other debater understand what is being said..well..why should we restrict ourselves from having an educational and fun round? because it matches the preconceptions of some musician on hackernews about what 'debate' is? pish posh