Is there any indication that users (not designers, developers, businesses or "the industry") actually want this?
It's just a question of degree. I'm sure some people want all their info to come from just 1 site, but most people want it separated into manageable chunks. Car info from this site, computer from that site, etc.
For instance, I come to Hacker News for most of my computer-related news. I use reddit for most entertainment, though there's some computer stuff there. I use Flipbook for random things that I wouldn't think to subscribe to on Reddit.
And people use Facebook, etc for things that their friends like and want to share.