The social aspect of the internet changed with blogs, youtube, and social media. People with shared interests getting together on fora has proportionally declined, people putting their lives and interests in individual display cases has proportionally increased. It's very tempting to put content in a place where you have 100% control, and don't have to answer to every random passerby.
That is, until you see what happens when it turns into a big echo chamber. Long live Home-Barista, Coffeegeek, and all the other places where you might hear something from all the annoying people who you haven't hand picked.