All valid points but there is another perspective to this whole mess.

I see it through my family members who all have Facebook, how they connect with relatives across the globe and routinely stay in touch during birthdays and other events.

I also see it at most social functions around me that organize over Facebook, because I am left out of those since I don't have an account.

My best connection to social gatherings is a friend who also hates Facebook but is a lot more social than me, moves around a lot more, so he hears from all the people with Facebook what is going on through word of mouth.

So that's a pretty neat service they're offering to a substantial part of the population. But of course they're suffering from moderation issues, something we can see on all large platforms like Youtube and Twitter.