It’s a barely hashed together spec for associating webpages. It doesn’t seem to offer any of the “value” that social networks do, the prime of which being an easy-to-initialize profile with copious features.

It could be possible with nerds/geeks. However, that group (in the early 00s, at least) was far more interested in keeping their online anonymity prime and avoiding social networks; so I could totally see why it was dead in the water.