i like how even though the game has millions of dollars of funding and yet it's windows only. well, it doesn't matter anyway, i was going to get it on xbox anyway.
Macs require a stuff ton of emulation. They do not natively support things like DirectX or almost every single other programming interfaces that Windows supports.
To make a game compatible for Mac requires jumping through hoops. In some cases, jumping through those hoops would require sacrificing things. In just about every case, the developer chooses not to do that because then Mac users would probably complain about a lack of "x" feature or whatever.
tl;dr: Some games go mac some games don't, if you wanted to game you should've picked Windows :/