Darktable is anything but "excellent", and has been, in my view, unusable for close to ten years.
One tiny example: https://github.com/darktable-org/darktable/issues/7332
One tiny example: https://github.com/darktable-org/darktable/issues/7332
(Most) users are not going to adjust their core working styles - which have been consistent on the Mac platform for 35+ years - to use a piece of software that gives inferior results, just to save $10 / month - which also gives access to Photoshop, for which there is no true replacement in any case.
And as mentioned in the issue you linked it isn't a bug but a feature request to support macOS hotkey conventions. There is a workaround in the meantime documented and a suggestion on how to address the feature request (that requires refactoring of the codebase) on the non-dupe ticket.
Since this is libre software anyone can improve the code along those lines and send a merge request or even commission a developer to do that refactoring; the DarkTable maintainers _didn't_ refuse contributions nor marked it as wontfix however that doesn't mean that the maintainers have development-time to spare in that macOS-specific code.
On the other hand if not using macOS hotkey convention is an example of it being "unusable" then I guess it is really great for something most people don't pay a penny or contribute otherwise for.
One day I wanted to improve getting started documentation in open source f.lux alternative for linux, because it didn't work for me in Ubuntu without any visible error. I found the solution investigating terminal logs and did a 5 point write up "How to setup on Ubuntu".
Readme pull request got denied because "only one point applies to Ubuntu" (others were applicable to other distributions, too). Somebody even commented few months later that he found my pull request and it helped him make it work on his machine.
This mostly made me stop contributing to other projects.