That would probably have either a negligible effect on sales or have a small upside overall. People who would buy a Mac to use with Linux are people who are not using macOS already. I would love to use the Mac hardware but I ain't giving up on Linux. The question is whether there are enough of us for them to make it worth providing support to Linux. Unfortunately, probably not.
I can do almost anything on a Mac terminal that I can do in a Linux terminal. So to _me_ there is nothing that a dedicated Linux environment can give me that OSX can't.
How about a usable package manager, or a usable window manager? Brew is extremely slow and cannot do versioning (as in, installing a package will result in random other packages upgraded across major versions), and for window managers there are only two non-paid versions which are OK but still poorer than alternatives available on Linux.
Versioning is done through the package maintainers. If there is no versioning for the package it's not Apple's fault (you could argue it's brews fault for not requiring it).
If you think Brew should require versioning then open a request.
If you don't think there is enough free windows managers perhaps you should create one yourself or contribute to a non paid project to ensure your wants are addressed.
It appears your problems are with 3rd parties and not Apple.
Packages within Brew are versioned, but Brew is incapable of understanding that and assumes you always want latest on anything.
> It appears your problems are with 3rd parties and not Apple.
No, my problem is that Apple can't be bothered to include basic features in their software, thus requiring endless third parties to fill the gaps pro bono / for money in the hopes Apple doesn't one day Sherlock them.
