Except its not really a development issue, it’s as much a manufacture hardware support issue. If a multi-trillion dollar company doesn’t feel like supporting it’s ‘legacy’ hardware and it’s customers that spent a bucket load of cash on said Mac, then I don’t think it’s fair to expect a tiny software organisation like Blender to spend it’s very limited resources in trying to keep said legacy hardware fully running just the same as more ‘current’ hardware.
Keeping in mind, that ‘current’ hardware, from a Windows/PC point of view, can be a good 10 years old and still fully work. At least work as well as one can expect from 10 year old hardware.