I think it's related to the fact that people can't think of everything at the same time. Either all of humanity has to uphold privacy together like a mother clutches a child or there will always be a few good men who "go overboard" and negotiate away their privacy for trifles, but the real world doesn't really have much privacy, especially for young people (for good reason, sometimes). So people grow up without privacy and don't really see the value in it, or why it should be considered in day-to-day life. Then add on the obscure and technical nature (to most)of the internet and the magic behind it's curtain. Add on the fact that trendy things make people feel safe, making many falsely perceive security and trust in something that is familiar and has a facade of transparency, like a company would have in an advertisement.

Anyway, with a few more serious breaches of trust from tech giant, this might change. But, I'm not sure if people even realize what they are fighting for. Do they want privacy for privacy's sake, or as a matter of principal? Or do they want to rightfully retain the right to sell their own info, or at least get a cut from the sale to third parties? Or are they afraid of a Orwellian scenario(I think everyone is at some level)? Or are they just jealous of corporations making billions and want to criticize someone above them to feel better about themselves?