They have to hold that view, though, else their reason for existence disappears. How can students justify the high cost of hiring a professor, accepted on the premise of being able to make it up with higher future earnings, if they realize that the reason there is a spectrum of incomes is because some people can't rise into higher paying work?

You and I know that the mentally disabled person will never rise into a $500,000 per year job, no matter how hard they try, because of their disability. But your colleagues have to suggest that the mentally disabled person won't only because that person hasn't attended their classes. Their entire marketing strategy of getting students into their seats rests on it. Failure to communicate that to students means they soon find themselves out of job.