Hey nostr:npub1cpg5tqql4fwgyddxejwyq3lxezxrjxxfmta6xlmhgfhhdl6ffdkqpdy4rt sorry for the delay!
You're totally correct about Bitcoin subculture and nostr subculture being largly one and the same today.
Best way to explain this is to talk about the goals of each technology and the type of people that those goals attract.
Bitcoin was invented because Satoshi saw that trusting a central authority to produce and control all money was an inherently bad idea. Bad for freedom: it's a lot of power and power is abused. And bad functionally: nobody is smart enough to actively manage the money supply to benefit the people (the system is far too complex).
Nostr was invented because fiatjaf saw that trusting a centralized social media authority to grant or block speech on the Internet was an inherently bad idea. Bad for freedom: freedom of speech is a fundamental human right. And bad functionally: no organization can manage speech in a way that doesn't piss off users and their advertisers
The types of people that see the value in one almost always see the value in the other. Because of that, the subcultures are super intertwined.
I do think over time enough cool stuff will be built on nostr that it will attract users for simply being a better experience. At which point you will see the space much less dominated by bitcoiners. But we aren't there yet. And that core ethos will remain super important if nostr is to survive.