First off your rank is within your category of submission (compo or jam). So you are #776 out of #1010, still it puts 25% of the compo entries after you. If you look at the star-value for your humor rating it is actually your lowest score in terms of stars. To some extent this could imply that there are many non-humorous games. Which is probably partially true. However part of it is that people don’t think that the categories are optional when voting, which indeed they are. You can, as I think you should, skip voting for audio if the game has none (alternatively maybe you should vote 1 because many will think they have to give a vote on all categories and some will sloppily give 3s to most things). In that sense, in part, I would agree with you. But I would say that its simply a graphical thing. There could be a N/A button that you can click instead of the stars. Voting system is fine as it is.

Believe me it gets worse. I once made a game that I thought had decent graphics. After it ended, I was playing a game when I suddenly realized that it had placed better than I did in the “graphics” category. Nothing wrong with that, other than the fact that it was a text adventure!