These sites wouldn't be a problem except that Google inadvertently promotes them in search results---otherwise, they would be the tree falling in an empty forest and no one would bother creating them. Google promotes them because their algorithms are no better at reading content than the spam sites are at writing content (worse, actually, because at least the spammers can leverage existing human-produced content whereas Google has a harder time leveraging existing human comprehension). Spam in Google's results will continue to get worse until Google's search engine can actually reason on a par with humans, at which point we'll have reached the goal of strong AI.
Google does have a "Give Us Feedback" link. Admittedly, it's hidden at the bottom of the page.
It'd be really good to hear anything from Google about that link. Does reporting sites make any difference at all? Obviously Googlers cannot go into much detail, but it would be nice to know that it's not a futile gesture.
