The fact that they are customizing the software is not really the issue. The issue is that they are making a change that will remove significant functionality and in some cases completely lock some users out of their password database, which is a huge deal. Imagine if you wake up tomorrow, run a software update and then can't log in to your bank?
I imagine the reason this has blown up so much is that the maintainer never reached out to the upstream about this, and was rude and condescending when upstream reached out to them.
The snark here is unnecessary and completely disconnected from how people use these systems in the real world.
Deferring to “it’s in the notes!” means nothing if you have more than a handful of packages on your machine.
You should also clarify the assertion that packaging affecting testing target won’t eventually hit stable, because that would be a major change that I haven’t heard about.
I imagine the reason this has blown up so much is that the maintainer never reached out to the upstream about this, and was rude and condescending when upstream reached out to them.