I'm not trolling you. You're the one trying to act like a tough guy.
I'm disagreeing with something you wrote, because I think it's wrong. Celebrities and politicians are frequent speakers at universities, and neither group is brought in (as a general rule) because of tremendous intellectual achievements. In the specific case of Oprah, we're talking about a woman who came from poverty, suffered abuse as a child (allegedly molested by 3 men, beginning when she was age 9), got pregnant as a teen only to have her child die in infancy, found a way to get back to school and go to college, was a beauty queen, got into drugs, led a promiscuous lifestyle, and finally got (at least enough of) her act together and became the first black female billionaire. She's made it as an actress, a talk show host, a producer, and more. She was also the only black billionaire, from 2004-2006.