Well, there are a few reasons. One is that people are falling more and more out of love with reading and writing; another is that the university system doesn't give a fuck about writers. You don't need a degree to become a successful author (although business classes might help) and you certainly don't need to go to a prestigious university.
Universities are there to train people in careers that need advanced skills, like the STEM and medical fields. Truth be told, it's just not productive to be spending thousands of dollars to learn how to write. So why is the university taking your money? Because there are billions (BILLIONS) of people out there who want to become financially successful artists, and the university is more than happy to pocket those peoples' money to pay for the students who will actually accomplish something in STEM. Or sports, I guess.
So most of the writing classes you're going to see will not be geared toward writing as an art form but instead toward the composition of business correspondence or some shit. If you think this is bad, just wait until they start talking to you about PowerPoint; you'll want to chew your leg off.
The other thing is that the professor might not even be very good at English comp. When I was in uni, I saw quite a few professors who were well out of their depth on certain subjects, just because the university needed somebody to fill in the slot. Universities need English composition classes, but nobody (and I mean nobody) wants to teach those classes. You might be surprised what kind of jobs people can get that they are in no way qualified for.