One way to change the Nostr protocol is to simply implement the change in your software. If enough clients implement the change, it gets written down and formalized as a NIP.
Discussion
So, the one way to prevent one popular client from pressuring every other client development team to adopt their non-feature and end up with it as a NIP, like some sort of feature-virus, is for npubs who use those clients to scream their head off on Nostr that
WE DO NOT WANT THAT, DO NOT BUILD THAT. THAT IS A BUG, NOT A FEATURE.
Otherwise, you're going to get it, good and hard.