This might be an unpopular opinion in the tech-savvy crowd of HN, but while I agree with pretty much 100% of the points brought up in this article, I still disagree that leaving facebook is a net positive. I simply believe that as privacy violating as facebook is, as scary and orwellian their statistical analysis of my life and habits are, they have solved a very real problem for real people: social networking online.
You can argue that facebook benefits from a lock-in effect and you wouldn't be wrong, but facebook hasn't always had that effect. They must have been doing something right from the start to get that effect.
I remember around 2007-ish when facebook was introduced in my life as a kind of cool club for university kids (I think they had already dropped this idea by then, but I still remember "networks" being a thing), and joining I was struck by how it was everything that my other social networks was not. It felt "professional", it allowed a low-frequency update into people's lives that wasn't matched by IM services like MSN/ICQ/whatever back then, and as it developed it turned into a crucial tool for groups in school, events (a major thing for me as a student), and more.
There will always be people that say they don't "get" facebook, that anything you can do on facebook you can do with other technology. Well, if you're one of those people you're probably also one of those people who thought "meh" when you saw Dropbox the first time because you can easily put together the same thing yourself with an FTP server and version control. Well, the kicker is obvious: normal people who don't read HN can not. Facebook changed lives for people who "can not".
If you fast forward to today and look at how non-profits are run, how political organizations are run, how after school-groups are run, you might have a point saying they could use something else. They could, but not without losing functionality. The payoff is always "a worse solution but you get to keep your privacy". The reality is, almost nobody wants that (unless you're politically active in a repressive regime, but facebook does support Tor, so kudos to them). The basic issues from the past linger: who will host it, who will support it, who will pay for it? Are we going to use an e-mail list, a web based forum, how will we communicate and share content?
Like it or not, ad financed networks solve all these issues and people are more than happy to sell their browsing habits for that. I don't think that's changing anytime soon, because even if the minority ("you and me") may be willing to pay for a substitute to buy out our own privacy, most people won't, and then the whole point falls anyway, because the solutions will obviously not integrate.