I suggest you try and talk to some people who actually get positive value out of Facebook for an alternate perspective. The HN audience (mostly young, nerdy white men) have always been one of the worst demographics for social networking products, and they might give you the impression that it's strictly bad for society because they don't personally derive any benefit from it. But if you step outside of that group, you will find there are actually a lot of people whose lives are enriched by social products.

Incidentally, this is why Google+ failed -- it was a social network marketed to the kind of people that hate social networking :)