I guess trying to protect against edits, and HTML rendering, and nanny bots, and any other feature that not all clients are necessarily interested in implementing just seems like an impossible expectation to me.  I would argue that experimentation at this level is more important - especially since clients are still broken in many different ways anyway.

If users think that a client sucks because it shows raw HTML instead of rendering it the way some other clients do, that sounds like how progress ultimately proliferates.

As an aside, FWIW, I'm not convinced that clients that obscure original pre-edited notes will ultimately be deemed by consensus to be the superior clients.