They never did look realistic.I'd certainly argue that they often looked realistic.
As for looking 'last gen', I think that really requires a framework where you know something that looks better.
Which there might be a few games on PC that fit that. Well maybe they don't look better, but they look more consistent.
Do you not remember seeing Halo 3 and thinking "wow I can't imagine games looking better?"
What about Uncharted 3?
I think we're both in full agreement though, just using different words. These games never offered pixel perfect recreations of the world but at the time they felt like accurate video game interpretations of the world. Only as newer video games redefine the rules of interpretation do older games look dated. It's the framework concept that you mentioned.
But judging by the reactions to this thread the rest of you haven't experienced that framework for this gen yet