Score weighting?

I've always wondered why Danbooru chose to give simply additive scores. You end up having older images being rated the highest simply because they've been around long enough to accumulate votes.

Why not do an averaged voting system, one that also allows users to express degrees of sentiment (-2 for really hate, -1 for dislike, 0 for okay/neutral, +1 for like, +2 for really love). Sure, this would tend to allow new images to pop right on top, the opposite of the current older-are-higher problem. But this could be solved, for example, by treating images as unrated until they accumulate a certain number of ratings first (say, five sounds reasonable).

There would be many, many problems with that system. First, it's too complicated. Second, it wouldn't help the problem you're talking about: it would start a new class of older is higher starting from the date this system was implemented. Third, it wouldn't do anything at all for the problem that we're talking about, which is that explicit pictures are higher rated than safe pictures.

And I'm not even sure what keeping pictures as unrated until they receive five ratings is supposed to do.