Personally, I try to rate games that clearly have original graphics/audio a bit higher than those with premade assets (not that I'd rate those games lowly, but I'd cap it at 3/4 stars for art and audio if that makes sense). I know a lot of other people also give a bit of a boost to the original-asset-using games, so I doubt they'd win in those categories. If they do somehow end up "winning" in those categories then I guess fair play to them