I don't even know why we're talking about bash here. But for the record, this is a unique circumstance that affects only software which made the transition from GPLv2 -> GPLv3. Changing your license can cause you to fork away from some users. News at 11.
The number of devs working on OSX producing non-OSX applications is staggering.
Every deviation you make from stock is something else you have to put into. The onboarding docs and convince all your coworkers to install. They won’t. Or they think they will but will miss a step or machine. Or for language specific tools, they’ll use a multiversion tool like asdf or nvm or ram and have to reinstall again every upgrade.
It’s not up to me. It’s not up to you. It’s up to us. And if you can’t see that, maybe you shouldn’t be working with other developers. Or maybe you haven’t been and you need to.
It's a fair question, and "currently supported" is essentially meaningless.
(Yes we all know about macports and the other more popular but less correct systems, and yes most bash scripts should be written to specifically avoid relying on any special features exactly to avoid being broken so easily. These are both true and both beside the point. Fact is still, this is not only a "currently supported" system by some technicality like the final months of a 5 year lts release or something, this is the up to this very minute version of a massive install base, with a 20 year old version of something as basic and all-touching as the very shell itself.
I know about this so intimately because I actually have scripts that don't work because they were intentional stunts to see just what could be done without forking any external exes or even child shells, but allow using every possible feature and trick in bash itself.)