The REASON why it was highly specialized, though, is that the idea is that the folks that were public, the artists, would be what everyone centered around. It was never about an individual building their own brand and getting to know and influence millions of other strangers. Apple, in this current iteration, would never create a platform where people readily and repeatedly provide private information on themselves to the public.
And, looking at it from Apple’s side, with the amount of moderation that would be required for anything starting up today, it would be a massive money sync without even the barest possibility of making a profit. The closest Apple would ever get to a social network is Ping or something LIKE Ping, and no one is going to pay to be on that.