Creative Suite stuff, which actual pro creatives use, on the other hand, has been 50-50 Mac/PC sales, even though the Mac has 10% or less of the desktop market.
That's how many creatives are on the platform.
If Krita can't tap into them, it's not the platform that's at fault...
Affinity, for example, does fine, as does Pixelmator...
It may be a wonderful program now, I don't know, but I do remember KDE's initial efforts on the Mac -- and they were... I originally wrote "just awful," but I'll amend that to a weaker "not very good." I haven't actually seen any desktop GUI program whose primary platform is Linux really take off on the Mac, with the possible exception of LibreOffice. We have so many good cheap-to-free alternatives.
In fact I used "webkit" before it was webkit and before it was cool: I used Konqueror as my main browser (I didn't care for it being not compatible with many sites at the time, as I cared mostly for simpler, text-based sites which worked fine).
I remember all the "KDE Office" apps, various drawing programs, etc. They were and many are on a perennial semi-finished state, in a way that Windows and OS X equivalent are not. Krita has done well on that front, and a couple of others, but it took many years of not great releases. And in Windows/OS X they are non-starters as ports...
... As a user, statements like that – about any platform – honestly just make me want to avoid anything from the developers who make them.
If a developer is going to attack users, the users are better off on Apple's side.
Apple has introduced Catalyst in Xcode -- this translates iOS apps to macOS, compile once and run on two platforms.
Mac App store has been notirous for not getting as much love as the iOS one but this change might reverse the direction as there will be a lot more apps coming for the Mac App Store now that they can leverage their iOS dev ecosystem.
I'm pretty sur once MacOS has switched to ARM, system partition will be in read only mode, you will not be able to install app outside of the AppStore except if you jailbreak thank to a "security flaw".
From an effort-to-income perspective, macOS isn't worth it.