Well I have to disagree on this one.
Because it really depends how you use it.
I have friends all around the world, many of them dont use email very often, they live on the other side of the globe so Im not going to call them either.... and thanks to Facebook I can keep in touch with them, we have groups/pages for our former classes and it is nice to actually be able to see what your old friends are doing, sometimes chat to them, send them a message and last month we organized a meeting - 10yrs after middle school graduation. And it was only possible thanks to the connections, because each one of us had email to maybe one or two other people, but because it is all connected, they all shared it and in the end we met up in quite a nice number of people.
On the other hand, I do agree that posting tens of stupid selfies everyday, spending hours and hours chatting to friends that live behind the corner or playing even more stupid FB games is an absolute waste of time - seeing that with my 18yr old sister....
I use it, but I dont post any personal info, dont post crap and I only make my contact details available to people I really want so Im not afraid about my privacy either. I agree that the FB hype is crazy, but meanwhile saying it is only for idiots... well ok, in that case Im an idiot too and Im not deleting my profile today. (btw. I was actually one of the first users of FB in general.... about 8 yrs ago I think, no groups, no chat, no apps, no pages... it was nice, just friends, the wall, but it is still usable)