My physics professor was a 26 year old with his PhD from Rice University and was just the opposite. On the first day of class he asked how many of us were going to to become research physicists. Seeing no hands he said great and proceeded to teach physics for engineers. He got in trouble for not “weeding” enough of us out.
I don’t think it really weeded out a bunch of folks. They dropped the course after the first test so it didn’t hurt GPA. I am guessing they hoped for a new professor the next time around.