Personally I joined mostly because of the protocol in itself and the various clients being built with it.
The "social" part came later for me, but I don't regret joining, I too started making posts only after someone followed me for a like I gave.
The issue here is that the general public don't know it's existence yet. And you can have more people only when the content is there already, your reasoning is absolutely on point.
I as, a member, am planning to do more than just post some thoughs in the near future, but surely I still can only appeal to a limited audience out there, we just have to share the most we can about all we love.
If nothing is there and you can share it, just do it and surely more will join you (me included).
A community grow one person at a time after all. 🫂