The conceit here is that the reply input is "just a textarea", and so when your focus moves somewhere else there's not a selection inside it any more. Since there's not a selection, any actions that require a selection to exist in order to do something get disabled. I think our specific intent (though it's been a while so I might be inventing this) was to indicate that the toolbar wouldn't have any effect when your focus was in the subject or summary fields.

I actually think that the way the 2010/2017 source editors work here is extremely confusing, because when your focus leaves them they preserve an invisible selection and act on it in a way that's impossible to predict unless you memorized its location. This is great in the "oops, I missed the toolbar by 2px" case, but less so if you went and wrote your edit summary and lost track of where you were.

Then disable them only when the focus is inside the summary or title field (which I never use because I've disabled the new topic creation and hidden the summary field). That is such a bizarre argument. I've just described actual harm it causes that I experienced and all your points are vague and hypothetical.

The more I think about your reply the more absurd it sounds. You're also describing a problem that would be a problem just once per user, even if such a person actually existed. I'm describing a problem that persists and potentially becomes worse as I get older.

Funnily enough, the MediaWiki-extensions-CodeMirror button is always enabled... cc @MusikAnimal

Yeah, that's because it's the only button in DiscussionTools that isn't related to a selection inside the surface.

That makes even less sense (which is possible somehow). All buttons on that toolbar is related only to the textbox right beneath it. And replying only when you have something to say in preference to addressing a report of bad UX is appalling.

Nardog, I appreciate that you disagree with me about the rationale for this behavior, but please consider moderating your tone here. Reasonable people can have different takes on what the best way for a feature to behave should be, and the phabricator etiquette guidelines suggest that veering towards personal attacks is not the way to address these differences.

I'm sorry, I found your commenting so quickly on something so tangential when you didn't comment on the substance of the issue for weeks (passive-)aggressive. That's not to say anything about you personally, but I hope it goes without saying if you "disagree" with someone's negative experience without concrete counterevidence, that's going to provoke a certain kind of reaction in them (whether they show it or not).