I agree that searches are jam packed with crap videos. That is why youtube Pete said favorite the good stuff and make play lists.
As for fail 3D, uploading videos separately for each eye could reduce that. Making it an interfaced upload instead of a tag. If there is no second video, ignore 3D. If there is no detected difference between L and R videos, suspend the publishing until a moderator can review!
There actually are a lor of very good YT3D videos. The problem is they are buried under both crap and the same videos that come up in a search every time. Unfiltered search of YT3D all ways brings up that broken cat video up top, the youtube guy, possibly Pete? The 3rd is always mosquito highway.
I'm not sure why but that is pretty broken when only certain videos can get top in search.