Appropriation is the idea that ate the art world. Go to any Chelsea gallery or international biennial and you'll find it. It's there in paintings of photographs photographs of advertising sculpture with ready-made objects videos using already-existing film.
I don't think there's any independent cartoonist whose stuff I don't like or respect in at least some way or another. We're all marginal laborers - we're practically medical oddities - so I don't see why we can't all be nice to each other.