Compound to that the repulsive nature of overly charicaturised videogame characters, the "necessary" association to the nitty-gritty, and you have a recipe for an uncanny valley.
However, a movie like Brave tells another story. There is some incredible photorealism there, and good caricatures, but it's done right.
But then this is stupid imho:
So, I think it's a tricky concept, but photorealism done right works (e.g. no uncanny valley), it just all depends on how interesting your characters are. Some things can fool the human eye, as long as they're done right. Animation and drawing have captured the imaginations of humans for ages, and lately with the advancements of Pixar and company this has not changed despite the leaps in photorealism. Yet, we continue to be drawn in. That's because it's well done.
soulless-serious-nitty-gritty =/= photoreal.
