Not claiming that to be a solution, just pointing out that no one can stop clients from doing that and thus putting whatever content type they want on a note, just like it happened with inscriptions.
The threat of a potential contentious NIP like that might put pressure into supporting markdown in a more sane way.
Sure, clients can do anything, that includes things that are much worse than Markdown. No protocol will survive if everybody starts to do awful things -- or if a single dominant client does "embrace and extend" techniques. Nostr is very fragile.
However the Markdown issue often happens because client makers want a way to automatically turn URLs into links, so they add Markdown libraries, not realizing the evil that would bring, so what I am doing is telling them.
Do you have any long form anti-markdown rants I can look into? I want to understand
