Why is there an assumption, that we'll be able to keep AI off Nostr, if we so desire? Why do people assume that paid-relays, are immune to bots and spamming? Nostr is tiny. Why wouldn't a spammer pay a couple of cents, to spam on a premium server? Hell, it might be stolen money or coming out of a rug-pull.

Why is there an assumption that bad actors wouldn't pay?

Hasn't Twitter shown that this is complete nonsense?