I take it you re not a gamer. If you like playing PC games and if you want to buy an oculus rift using linux or a mac is not an option.
There are a few games that I play that are compatible with OS X, namely SimCity. Another games have been ported, they're not as optimized as PC games are but if you buy a Mac you probably knew that before you made your purchase. Before I bought a Mac, I was a PC gamer for 15+ years of my life.