The problem is that online criticism has a similar crap-to-gold ratio as online fanfiction or teenage goth poetry on LJ, with the extra twist that the worst of it is not just rubbish, but actively nasty and horrible. I've read some great insights into TV, books, music and films online. The trick is to find ways of filtering out the bottom 90%. In the world of traditional publishing, that's what editors are for. In the freedom of the web, you have to find your own way of filtering. There are various ways of doing this - a judiciously chosen friends list on LJ, websites and blogs that aggregate or link to the best online criticism, and so on. I don't know which way is best, but I do know that avoiding the open threads on Doctor Who Forum after a story has aired is a pretty good start.
It's interesting in itself, but it made me think about modern filtering strategies. Making use of the web is all about filtering out rubbish, and I don't think those who predicted the modern influx of information, predicted very well the strategies that we would use to negotiate it. Specifically that we create and maintain social networks which transmit and filter information quite efficiently. Funny it wasn't well predicted because these strategies involve long established human behaviours - like reputation, co-operation and reciprocation.
And I think that SF novels which predicted futures dominated by computerised information envisaged that it would be controlled by corporations, or by governments. Also that it would be mediated by money, and access to messages and information would be either restricted or imposed by centralised fiat. Perhaps it was because they extrapolated a kind of super-television model.
I know I am always going on about it, but I think the most accurate prediction of the modern Internet is in the Mars Trilogy (I know the Internet existed by that point, but it wasn't anything like it is now). For instance there's a passage in Red Mars where he describes a video of the Space Elevator falling, which someone has cobbled together from clips posted from hand-held devices, putting them in chronological order, and adding a music track. It's exactly the sort of thing that would appear on YouTube nowadays. Red Mars comes across as soft and idealistic, and yet it has correctly predicted how people work for nothing to create complex information landscapes.