I don't think he's claiming the variation in content has decreased, but warns that dependence on collective rating systems could decrease the variance of an individual's effective sample size.
I also don't think the author claims the web has introduced any social problems, just that it isn't solving them yet. Are these even problems with technical solutions?
I also don't think the author claims the web has introduced any social problems, just that it isn't solving them yet. Are these even problems with technical solutions?