MacOS X is not a version of Linux, and in fact it diverges more with time (e.g."Metal" instead of Vulkan/GL). Porting to it is very different. Also, there is no incentive as Linux users don't complain as much about having to run the game in Wine. Linux users also don't show up well in statistics for this and other reasons. Also, for small studios, it is not worth porting to a platform you are not familiar with.

The developer develops on Mac and ports to Windows. He has tried porting to Linux twice (the original Exile III: Ruined World and Avadon: The Black Fortress). Both times porting was more trouble than it was worth.

From what I've read, he has no plans to make more attempts at porting in the future even if someone would subsidize/pay for the port like Humble did with Avadon: The Black Fortress. According to him porting to Linux was far more work than many people imagine or claim and required far more support than Mac and Windows versions. Sales on Linux were also pitiful compared to other OS'. Pretty much only way port would happen is if someone else made it and would also take care of supporting the port.

I can't even imagine WHAT he could develop in, in Mac, that wasn't rooted in either Linux or Windows. It's not like Mac has the corner on development languages, ..or, ANY languages, actually. I'm not aware of any Mac specific development languages since that AppleBasic disaster decades ago.

I've ported more than my fair share of apps to Linux, I'm calling B.S. Sometimes you might have to set up your own development environment, but that's kind of a no-brainer, isn't it? ONLY Linux has the apps that let you just drop a bunch of junk in to a catalog, and then use Make to create an installer. Anyone else coming from any other environment should be totally used to setting up a development environment.

As far as the different Linux flavors go, that's been butt simple for over a decade. You simply upload to the SUSE development website, then use that to automagically create installers for the other official flavors of Linux. I don't know how it could be simpler.

The developer shouldn't have to develop in to Wine. That's just silly. Wine is the emulator. If the developer is developing for a stock Windows OS, then Wine needs to adapt to make sure it works in Wine. Of course, nobody DOES that, because Wine is a free, open source project. That's why people need to PAY to have Crossover Office or one of the other Wine flavors make their apps compatible.