Really now, if your stance is "it is bad for an open source maintainer to make decisions that might be difficult" then it seems you would have trouble finding any project that suits you.
The argument was that it would lower cognitive load, without any evidence backing it up, and obviously with no input from people who regularly have to mix different input systems - where the ability for IME state to match context of the window they are in, especially as sometimes the different tasks in different windows would have incompatible needs on current IME state.
I'm posting that because (a) I believe that is the issue referred to, (b) if you look at the reactions there is definitely a lot of "why would you even want this", there is the "lower cognitive load", and they did go ahead with a release in which it was broken, even though it was reported before the release was finalized.