I don't agree at all. Facebook has been a controversial thing almost since it started, and now it's just being used as yet another scapegoat.
Facebook doesn't make us lonely, and it doesn't make our lives crappier. All the tools we need in order to change our situation are right within us, right in our hands. So what if 20 of your FB friends all changed their relationship status to "in a relationship" on the same day (as an example)? It doesn't have crap to do with you (unless you're the one they're in a relationship with...). If you don't like it, delete your account. But don't keep it just so you can log on once in a while and afterwards complain about how crappy it makes you feel. It's just so comfortable blaming our pain on a faceless entity. And even better because Facebook isn't going to actually defend itself, thus giving us a feeling of automatic win.
I'm amazed at how many people I've recently heard say that Facebook "makes them unhappy", or "is to blame" for depression. Because what? People have the audacity to post "happy couple" pictures? By that reasoning, any gesture of affection between couples should be prohibited out in public as well, lest some lonely person sees it and feels horrible afterwards.
And sure, so many hearts get broken because people catch their partner cheating on Facebook, thus Facebook is evil. Really? So if someone walked in on their boyfriend humping some other girl, the heart wouldn't be equally broken?
Cut it out. Give Facebook a rest. If you're miserable, the reason is within you, and so is the solution. Stop looking for scapegoats. Change something about your situation. You can post your success on FB, and try to make others unhappy with it, because that's what it's there for, right? To make others unhappy? And make sure you never smile or laugh loudly out in public, because some miserable person may take offense to it.