I think most do see bitcoiners, and think this is a bitcoin group, and that's it. No more complicated then that. Just someone told them try nostr out (you can own your account, etc.), they came, found out it's all bitcoiners, they don't care much about bitcion, so they left. That simple.

If someone told me to try out a social network that "lets you own your account", and I jumped in to check it out, and all I saw it was all Warhammer 40,000 people posting Warhammer 40,000 things, I'd be like 'well I guess this is a Warhammer 40,000 club', and I'd jump out.

I don't think big picture stuff like how this compares to the centralised experience even has time to enter the picture. People are out before they've even kicked a single tire.