Apparently yes. At the time I would probably say no. It depends on the argument being presented and not on who is presenting it. Though the messenger often times becomes the focus of the debate. In the case of Zuckerburg I don't trust his motives and - here's the rub - he's in a position to abuse trust.

Now if a dictator is in favor of eugenics and starts talking about increasing contraception one might reasonably fear what comes next. When someone is not in a position to takes things to the next level then their ulterior motives are not relevant.