"Mass exportation of email is not standard on most social networks — when a user friends someone they don’t then expect that person to be easily able to send that contact information to a third party along with hundreds of other addresses with just one click."
http://techcrunch.com/2009/10/26/orkut-slows-hemorraging-to-...
Google was right then, and Facebook is right now. You have a right to download the data you put into Facebook, but not the data your friends put into Facebook: their photos, status updates, check-ins, and yes, contact information, are all technically readable to you, but this is information your friends have contributed, not you. Providing bulk download of other people's data would be widely abused, and lead some of the same critics of Facebook's "lack of openness" in this decision to complain about Facebook's "disregard for privacy" if it were reversed.
I work for, but don't speak for Facebook, just my opinion, etc.