I can't speak for anyone else, but i wasn't that upset with Romney. I mentioned it as obnoxious but actually said that overall Romney didn't come off as obnoxious as he usually does...and i think he clearly did better overall. And then this time around, i acknowledged Biden's behavior as probably off-putting to deciding voters, but said that i think overall he went out there and did what he had to do.
I had been thinking that after the responses to Romney, that people would have been equally or more upset with Biden. Instead, people who were appalled with Romney, thought Biden's behaviour was fine.