I came here to say this and can't believe I had to scroll down so far. All you need are accurate tags and a way to filter by them. There is no point punishing people for submitting or voting up something the community is not interested in. Just make sure they tag it correctly so that it can be found or ignored according to reader's preference.
Note this discussion is exactly akin to deletionism on wikipedia – if we can categorise information effectively, why reject any of it?