When someone was too embarrassed to ask a "stupid" question, we would have the "Designated Idiot" ask it. The professor might sigh a bit, but would always give a more complete answer, so the rest of us understood the material more completely.
And there were benefits all around. In a series of classes, we had a professor known to subjectively ding student's grades for "dumb" questions. Our "Designated Idiot" kept the class grades a bit higher as a result. In this class and others, we noticed that our "Designated Idiot" tended to get a higher letter grade than the test scores might have suggested.
In many cases, while it interrupted the flow of the the class, the professors saw the benefit in quizzes and tests on the topics. When the "dumb question" had been asked, the material covered was retained far better by the class.
So don't shoot the idiot. Find them a role that helps everyone!