It would seem that the problem is they add value to people's lives and reached ubiquity before laying on the cost (mining our data and jamming ads in our faces.) Now, arguably, a large part of the value they provide is alleviating our fears of missing out, since everyone else is signed up. It's similar to smoking's bait and switch: at first you get a little buzz and it's novel, but nicotine cravings slowly raise your resting anxiety level to the point that the relaxing effects (returning you from the artificially high anxiety levels to your more natural baseline) is the reward.

They really have high jacked out psychology-- we've learned enough to build blunt tools to hack our source code, and it's no surprise that this is the result.