I don't understand all the fuss. The main failing on the whole Apple strategy has nothing to do with the OS, never has. It's those sky-high hardware prices.
The strength of Linux has always been a Unix-like OS that runs on commodity hardware. It's two elements Unix + Cheap Hardware that make it such a powerhouse. Hell if we were trying to sell Linux entirely on the OS we'd have a tough time competing with existing Unixes.
OSX only runs on Mac hardware. Mac hardware is pricey as hell.
If people like the OSX GUI, then turn it around on them, make a OSX compatible system that runs on commodity hardware and put apple out of business at the same time you put MS outta business.