That’s akin to use hacked or pirated Windows ISOs to build and test Windows-software. And nobody in their right mind would suggest that, right?
Why does different rules apply to OSX?
Also: DMG-files can’t be used unless you’ve already purchased that $1000 machine you don’t really want/need. It’s completely unsupported in any meaningful sense outside OSX.
So more roadblocks.
You know how I get a Windows ISO? I download it from Microsoft. Ubuntu? Download it from canonical. Etc etc.
Can we all agree that it is Apple who put up all these roadblocks?
No other OS vendor makes it harder/more expensive to support their platform than Apple does.
And then you can’t really blame developers for not bothering. It’s all on Apple.