Not to defend Facebook per se, but "managing privacy intuitively" is hell of a user interaction problem. I don't know any design that could encompass all the complexity of human social interaction and privacy issues related to it intuitively.
A few people who can't be bothered to back up their own work and data, nor to respond to announcements of upcoming changes, may be pissed when items are "lost". But no one's privacy is compromised. Further, if you provide clear means of such a back up and/or instructions and advisement to maintain private copies, you can help lessen this second problem.
That's something to Google's credit, that they've officially supported and developed means for users to retrieve their data locally into documented, usable formats.