I don't care that RGIII runs; it's that he doesn't seem to have good instinct for avoiding a hit. At least not now. When I watch him it seems like he's diving forward a lot, or off balance when defenders are there. His ribs and his side are exposed.
McNabb ran but he cut down on that a lot pretty early, and he bulked up. And he knew how to avoid big hits. Steve Young is maybe the closest running comparison, to me. And he lasted quite a while, so maybe RGIII wil too.