Also we have to consider that "regular" Internet users (who are probably not HN readers!) just want to communicate with their friends, share pictures and jokes,

Also we have to consider that "regular" Internet users (who are probably not HN readers!) just want to communicate with their friends, share pictures and jokes, find news, etc. They want a simple user experience that's just easy to use. THAT user experience (UX) has been the main issue I've seen with attempts at a distributed social network (such as Diaspora).