This is a pretty naive take that assumes the only relevant parties are the various library authors. The real issue here is the hours and hours of useless maintenance work breaking changes routinely force on anyone writing software with the supposedly "modern" tech stacks. Sure, maybe this change adds a minute of work for someone using flask. How much time does it save flask's maintainers? More than 1 minute * the number of people using flask? Being more hesitant about breaking changes as a industry would eliminate hundreds of person-years of basically useless maintenance work.
> Being more hesitant about breaking changes as a industry
... would lead to even more outrage, because we tried that in the past. And the result were "rotting libraries", that became unmaintainable, incomprehensible, and riddled with hard to track and harder to fix bugs, because they had to drag along code that was often more than a decade old, kicking and screaming, just so libadbandonedsincebronzeage.so wouldn't have to issue an update.
So no, we should have breaking changes.
We should keep libraries vital and get rid of old code. We shouldn't drag along stuff just because we can. We have established procedures to deal with this, and with good reason.
