Hello, fellow mathematician. The first step in your proof which doesn't convince me is the claim that, in general, "levels of intelligence" exist, admit a partial order, and can reliably predict whether certain people can learn certain topics.

In general, you'll find that "leftists" believe that psychometrics is bogus in terms of science. Instead, it masquerades as science in order to fool the public into believing that biased public policy is neutral. There's no denial that some folks have brain damage, developmental disabilities, etc. but a denial that standardized tests are an appropriate proxy for genuine medical diagnoses.

Community colleges should present themselves as a public benefit. We shouldn't ask that everybody pass any class, simply that everybody has the opportunity to attend/audit any class. It is unfortunately true that the typical university administration is clueless and money-grubbing, preferring graduation rates to other metrics.