I'm in SE Asia right now, in a country where Facebook Zero makes it available to everyone regardless of income, and guess what? Not only does everybody have a Facebook account, many women have at least three: one for friends, one for family, and one that is anonymous to hide their activity from their friends and family.

I know it's against Facebook's TOS, but it's so easy to create a pseudonymous username. So it's the same for American teenage kids: they just create a new account with a fake name. If they are abandoning Facebook it's because they like Instagram or Snapchat more, not because their parents are on Facebook.