So the question becomes not "why is everyone using them?" or even "why are they doing things like this?", it starts with people like me who got to ask themselves honestly "why do I keep relying on these guys?".
Gmail is my main email account and it makes me deeply uncomfortable. I love OS X, despite its ever-increasing flaws, and that makes me feel like a hostage experiencing Stockholm syndrome. Facebook is the only thing in this category I actually stopped caring about on my own, but if I'm being honest that's more my friends' fault for re-enacting soap opera scripts online and offline, and less because Facebook is a data-grabbing virus that screws its users over at every turn (which it is).
My only face-saving answer to that conundrum is those products offer me some things that others don't, they have features that large companies are better positioned to deliver on. However, that's not a permanent state of things, as the complex features of yesterday become increasingly more feasible for smaller developers to tackle tomorrow. Maybe it's a good thing that Google and others are finally straight-up bent on filtering nerds like me out of their customer base, maybe that's the kick needed to overcome inertia and complacency.
