Who doesn't need employees that are thought leaders? Pitt is not a high school. Universities aren't just place for undergrad teaching. That's the difference between a community college and a university.I'd argue that higher education today has become much more like 'creating widgets' then in the past, except they want to keep creating widgets while keeping the price high. We don't need employes who are thought leaders in their field or who have terminal degrees to be teaching basic courses. 90% of things to learn in college can be easily obtained with a cheap or free online course or by simply visiting most libraries.
Tenure stream professors are expected to produce new knowledge in their field, perform institutional service, obtain funding...not just teach. They are bringing in, collectively at Pitt, over a $1 billion annually in sponsor research to Western PA.
Certainly it varies by the field, but just take someone in the natural sciences. A neuroscientist in Dietrich is expected to publish and present at international conferences their original high-impact research, obtain multiple federally funded research grants which pay a majority of their own salary along with the salaries of post-docs and technicians, supply their labs and pay overhead for their lab space, teach undergrad and/or grad school classes often creating their own classes and materials, mentor and advise grad students and undergrads conducting original thesis research, and perform service to the university with things such as sitting on a myriad of committees. Being a tenure stream professor, at least in the sciences, is more like running a small business than what I imagine some think as being a teacher. Outside of tenure stream, there are dedicated teaching positions, but the average of those salaries at Pitt is less than the average high school teacher salary in PA.
Students that go to universities like Pitt should want to be taught by international thought leaders...that's what they are paying for. The advantage of a place like Pitt is that they get to participate directly in this cutting edge, renown research and develop relationships with people in those fields. Anyone can learn the basics from a text book or on-line classes. That's always been true as long as there have been text books. Where you began to understand and critically think about an endeavor is by doing it and emersing yourself in it; whether it be in a lab, studio, or field. And yes, this is what Pitt undergrads, not just grad students, get to do.
If they just want a more surface knowledge of something instead of trying to develop a deep understanding, then yes, just go to vocational school or read the textbook at your local public library.