its about apple being able to optimize a program for its native OS, and to be able to provide better support to its users by doing so. you can have a team divided in two to write and support the program for mac and PC, but then you have to remember that there are waaaaaay too many variable hardware configurations for PCs, whereas with a Mac its simply a matter of which version of OSX you're running and whether you're on G4 or G5. of course it will be a bit more complicated now with the intel transition, but im sure apple has it under control.

so yea, death be to the PC!