I agree with Ryan that these kinds of sites are worse than scrapers because they're just as useless but algorithmically much harder to detect.
They're made to earn the employers revenue, not help out people with the particular queries.
I hope the point is clear -- "to earn revenue" isn't an appropriate test. But your point is well taken. I'd prefer a search to turn up the site made by the guy in the garage who is passionate about the subject rather than the $4/hr content farm content.
I think if we're to continue complaining about spam we have to actually define what we mean by spam. And I have this strange feeling that not everyone will agree...
So you don't want to just say "these are spam."
I recall about.com as a decent site a while ago, but I believe it was acquired a while ago by ... Yahoo!? Go figure.
I think that might be what makes it so complicated. [1]: http://www.quora.com/Why-doesnt-Google-push-down-low-quality...
About.com is owned by the New York Times Company, not Yahoo.