There is a passive scoring system for downloads: the download count. This is pretty useful for seeing how many people are downloading one of you submissions. However, I beleive it was determined that download count was not nearly as relevant as Favorites for scoring quality of assets. Many people download some assets to see what's in the package, but don't really feel they're terribly useful assets once they do. In such cases, the download count is not a good reflection of how popular the asset is.

Granting points for number of downloads would encourage submitters to submit several, more trivial, works with potentially misleading previews in order to gain more downloads. We'd much rather have fewer submissions that are more consolidated and higher quality. :)