I can definitely see his point about new social networks - probably the biggest win Google+ has given me was the ability to start my social network fresh, with only interesting people (also, mainly nerds, so I now post geeky stuff to Google+ and stuff my family/non-technical friends would care about to Facebook).
That said, this is also a problem of his own creation - I keep a fairly lean Facebook friends list (which I'll purge of local contacts I'm not close to after I move next week), and fairly often unfriend people who I'm not close to and consistently post things that don't interest me.
