The guy just came back from an injury that scrapped whatever build up he would have had in the months before the rumble. He had nothing going for him. I have no doubt he would have been the last guy on Cena's team at SS, so I think that would have warmed him up a bit with the crowds among other things.
Not to mention you had Daniel Bryan in the match too, and there was no way in hell anyone was going to be a cheered as much as that guy. (It also might have helped if he won the Rumble last year like he should have so his elimination wouldn't have broken the crowd.)
Of course, even if people liked Roman, that wouldn't have made the Rumble match suck any less.