Talent and success in any field do not guarantee a good teacher, but famous people get gigs at top-notch schools all the time. Sometimes it makes sense, like Al Gore teaching current affairs at Columbia, but things get murkier when big-name stars become big-name professors. After talk about James Franco being a TA at Yale fizzled, he is going to the head of the class at New York University when he teaches film this Fall.
James is a curious mixture of experience, education, and ambition with no boundaries, but he's not teaching acting or the 168-hour work week; he's teaching directing. His IMDB page lists nine directing credits, which are mostly for short films. He's definitely qualified, but is he the most? Maybe — he certainly knows showbiz's current climate.
Not that NYU's Tisch School of the Arts, where James will teach, needs to advertise — it's one of the most sought-after film schools in the country — but it's obviously good PR for the school. So when celebrities — political, film, or TV, — are hired to teach, would you say it's more for their experience or their name?