He was definitely a disaster, but I am not sure what coach, short of Lombardi, could have come in and had much more success. Fan support was dwindling P's last few years. Nearly everyone was calling for his firing, but no one had a better solution. A lot of people point to Ray Rice backing out of his commitment as the downfall of SU football, but according to most recruiting rating services (which I recognize as complete BS) Robinson got "better" commitments in his tenure than Rice. In fact some of Doug's success was also built on Robinson recruits.
I think Greg Robinson was too eager to get a head coaching gig and jumped at the first opportunity. Had he done more research he may have been like a few others who said, "Thanks, but no thanks."
Don't misinterpret this post as me claiming Robinson was anything but a complete failure at SU, but I do think he walked into a shitty situation and despite his best efforts couldn't change it.