Do we really believe that rhetoric?
Okay, should two professors at the same college in the same department with the same credentials get the same pay?
Well, when I was at university, I had a professor named Walter Metz. I remember his name seventeen years after having seen him in person for a reason - I learned more in his class than I've ever learned in any other five month period in my life.
His class was hard enough that, out of a hundred and seventy students, more than a hundred dropped the class after the first midterm. He graded on a curve because, realistically, the best student would get a C. Because he was grading on a curve I ended with an A- with a score that probably would have landed me with a C otherwise.
His tests were all hand written with short answers and essay prompts that we had to respond to. He didn't only read everything that every student wrote and score it, he gave notes, he analyzed everything that we wrote - often with bad penmanship and poor grammar - and gave us feedback. He accommodated a friend of mine with dyslexia and went out of his way to do so. In order to grade our first midterm, since every person was given three essay prompts, he read 510 hand-written essays, thought about them, analyzed them, graded them, and gave individual feedback.
I had another professor (whose name escapes me) in the same department who gave multiple choice tests which were often confusing. I had a meeting with him at one point in which I explained my reasoning behind an answer, told him how the wording made two of the answers technically true, and asked him to take that into consideration. He didn't.
This is why meritocracy should be a thing. Walter Metz should be a fucking millionaire because of how good he is at his job. No other professor that I ever had working the same job at the same institution with the same credentials should be earning a dime for every dollar that he makes.