A few years ago when social networks were all the rage this was discussed a little in the forums. I can’t speak for EE of course, but I believe they just decided it was a road they didn’t want to go down. Now it looks like that was a great choice.
There are still a few scripts out there to do it better than EE (a social network), like the blog hosting ones (bloghoster?), but it appears they suffer from poor support and aren’t even close to being anywhere near as robust or well developed as EE.
Good luck though in your project, I am sure you’ll find a good compromise if you try!