Offtopic, but I think a huge reason for that is how fantastic the Apple Frameworks are for any Pixel/Vector/GPU/UI stuff. Quartz Composer offers an API to include it into apps, there's CoreImage, CoreVideo, Quartz2D, SceneKit, CoreAudio, and much more.
SceneKit [1] alone, makes it unbelievable easy to create animated 2D/3D interfaces that combine various media types.
Due to this, it is probably easier to create a sophisticated design application for the Mac platform than for any other platform [2]
[1] https://developer.apple.com/library/mac/documentation/3DDraw...
[2] Based on some reading it seems that Qt is starting to offer similar functionality, especially with regards to Filters/Pixels/Vectors, but I'm not really sure about that.
You may be right, and I'm no expert in this, but that is not a large part of the reason.
I think it was a well designed piece of software by itself - and the node based programming model lended itself well to interface design.
Right now, it is more a case of adoption. For example, Facebook is investing a lot of resources in creating stuff like Origami for Quartz Composer. I'd be willing to bet that if Facebook puts even a small part of that resources into supporting something like Blender, then the fundamental differences at the OS level should'nt matter.
SceneKit [1] alone, makes it unbelievable easy to create animated 2D/3D interfaces that combine various media types.
Due to this, it is probably easier to create a sophisticated design application for the Mac platform than for any other platform [2] [1] https://developer.apple.com/library/mac/documentation/3DDraw... [2] Based on some reading it seems that Qt is starting to offer similar functionality, especially with regards to Filters/Pixels/Vectors, but I'm not really sure about that.