Because it's not a privacy issue. Privacy is the red herring. There's already ways to protect your privacy online. Additionally no one wants online privacy. People spend long hours making their facebook page
People make Facebook pages because they think they can control who sees them. Also, different cultures value privacy more than others, because they have more experience with the risks of a lack of privacy.
I suspect that's because no one has access to whatever data has been gathered about them, and so it's hard to draw a mental picture of how that could be (or is) being exploited by corporations which apparently believe that they are above the law.