I mean, let's just admit that you don't have to be a Facebook user and you don't have to sign a Facebook TOS for them to accumulate data about you, so it's not quite as cut-and-dry as you make it out to be.
As far as the "good" and "evil" parts of the stack... fair point. I think most devs are somewhat abstracted away from the collectively malicious vision, since most of the constituent parts are relatively benign on their own -- "let's identify faces in photos!", "let's automatically identify faces in photos", etc. It's product folks, or maybe even higher up than that, who connect the powerful pieces produced by devs to actually make Facebook the monster it is today. I'd guess that even the devs who have impact on that vision don't really have the power to dramatically sway that vision, they've got a bit of technical input at best.
Still, have you ever worked on a product you don't believe in? If you're just cashing in a check, I guess it could work, but if you're as idealistic as me you want to work on something that's doing good in the world. Especially when so many tech companies proclaim their intent to "make the world a better place" or "do cool things that matter."
Not really. Many people just feel they have to use Facebook to connect with the society efficiently. Some people even consider those who don't use Facebook weird.
All of these products are designed to be as addictive as possible (to varying degrees). The whole point of of an addiction is that your are there voluntarily. (Not saying facebook is as bad as the things above, just that they are all designed to addict.)
Or we could have a legal system where everything is forbidden except for those things explicitly allowed.
Slack vs irc
Facebook vs myspace vs geocities
I hope this is sarcasm.