It's like most other unfiltered sources of information on the internet: mostly worthless, sure, but we do get some good suggestions. Even on obscure topics, how many of the top 100 Google results will be listable sites? Is MSN search any better? Ordinary site suggestions are widely known to be 90% or more spam, but the rest amount to dozens of new sites found daily.
We don't want to lose these information sources -- low as their S/N ratio is. But the point is, all of them are very unreliable authorities, and we certainly don't want to set any of them up as ANY kind of authority. Just suggestions, that's all.
So don't think of it as "they refused to serve me!" or "they're disobeying my command!" It's "I made a suggestion; they'll deal with it on their judgment of its merits, not mine."