The first time someone told me about nostr, I was pretty worried about the fact that keys can't be subbed and repudiated.
Thinking more about it, it's mostly a problem for non-bitcoiners. Bitcoiners know how to protecc keys.
Keys that can be deterministically generated and recovered from a "master key". Each subkey can have a different role, say, for different note types (posting, liking, etc...). Subkeys can be abandoned or lost with signed public messages saying they are no longer valid and have been replaced by another subkey, created from the master key.
Subkeys are definitely important. However, I believe there are already NIPs addressing that.
Dismissing something as a joke at such an early stage, especially when the problem is recognized and being worked on, is foolish.