Pre-RFC improved ergonomics for `!`

I appreciate the work you've put into coming up with a bunch of cases where ! has awkward ergonomics ... but I don't see anywhere in this pre-RFC where you actually explain the change you're proposing. What exactly do you want the compiler to do with ! that it doesn't do now? Or not do, that it does?

I'm pretty sure you meant to have a section explaining this, since the "this won't work because ..." section is responding to critics of your proposal; did you accidentally cut it when editing?