...except you are only listening to his parenting advice compared to, say mine or the GP, because of his relative narrow expertise in a completely unrelated area. I'm not calling for famous people to STFU, but to be extra vigilant about passing on advice outside of their recognized area of epertise. For example: should Jenny McCarthy "stay in her lane" or are you cool with a c-grade actress using her fame to promote dangerous pseudo science?
Perhaps people like his parenting advice because it's insightful on its own merits? I wouldn't expect an expert on startups to be particularly wise when it comes to parenting. If anything, I'd expect the opposite. But the proof is in the pudding.