For most people, it doesn't solve a pain point they have. This type of social network, for most people, is simply just nice to have, but not worth paying for.

For most people, it doesn't solve a pain point they have. This type of social network, for most people, is simply just nice to have, but not worth paying for. For some people, it's exactly what they need and solves their pain (or at least would if there are sufficient number of other users). But there's not enough of them, and the low number of such users isn't enough to sustain a commercial company or a social community.