Except that the very top of the professional high end is not really that populated by macs.
Most pro 3D designers use 3DStudio MAX (Windows) or Maya (multiplatform with no advantage for Macs). Most architects use AutoCAD (Windows only). Most professional studios use a mix of all three, with a predominance of Linux and Windows at the highest end. Even with audio there isn't much of an advantage to using a Mac unless you depend on Logic Pro.
While a lot of people moved to Windows due to Avid Media Composer issues with Macs in the mid-2000s they've been moving back since hardware support renewed. In the audio post industry it's at least 80% Mac-based in the US.
Actually, AutoCAD has a Mac version, though that doesn't change that much. But the point still stands — it makes sense for Apple to want professional applications, it doesn't really make sense to try and write own Maya, and distribution dynamics are for large packages are different enough to make using Mac App Store for them less attractive.
Most pro 3D designers use 3DStudio MAX (Windows) or Maya (multiplatform with no advantage for Macs). Most architects use AutoCAD (Windows only). Most professional studios use a mix of all three, with a predominance of Linux and Windows at the highest end. Even with audio there isn't much of an advantage to using a Mac unless you depend on Logic Pro.