These days where everyone and their dog, cat, hamster and parakeet are on the web, sites with content attracting intelligent people are likely to receive smarter comments than those targeted at average Joe. Simple as that. (As such, GH should fare better than average.) All-day life has moved onto the net, complete with everything associated with it - things like war not excepted.
The "old" idealistic internet is not dead at all, it's merely diluted in a sea of noise. So many of the things that are trendy nowadays promote a near-zero attention span and no attention to detail. The latest memes, tweets and Facebook updates may be fun, but let's be honest, the vast majority of it is just useless clutter that is wasting your time. When people are taking their time, they can end up with some pretty amazing hobby projects that make you wonder how much effort may have gone into them. (Not to mention some of the greatest inventions and discoveries of the last century or two.) You have to wonder whether a wider exposure of such things on the net really makes up for generally reduced attention spans.
That being said, the net greatly increases the visibility of things. We may not actually have become any less smart, but if any idiot can post on there, it'll show. It's the same as with the apparent flood of music we are experiencing - there aren't any more musicians than a few decades ago, their output has merely become a lot more easily accessible.
