> Being proficient in graphics doesn't mean you are an artist.
Really? What is required for "being an artist" other than, you know, making art and being good at it? We could forever argue about what things qualify one as artist, but I believe that having the word "artist" in your job title is one of them.
> I'd imagine that the useful things art school could give you would be art history, aesthetics, color theory, and criticism.
Looks like we also disagree on the meaning of the world "useful" =)
Seriously though, if you're interested in art history you can definitely learn it over the internet. Color theory is just one of the many skills you pick up as you lean to paint, and there's plenty of courses on that. "Aesthetics" is a pretty vague term, I think it is sort of like "taste" - it is just something you develop as you get good at what you do.
And when it comes to criticism - you can just use your own judgement or get a lot of helpful feedback on forums. Online classes like Animation Mentor offer feedback and critique of incredible quality, from people who have exerience working in companes like Pixar/DreamWorks/etc.
> Commercial work is certainly far removed from the art world.
I think that a lot of of the best art is now being developed as a part of the "commercial" projects - animated cartoons, movies, games.