As all the people above mentioned PC as their first choice, my opinion goes no different. It's of course PC bruh, because MAC is just like more of watching and less of utility kind of thing especially when talking about games.
PC provides you a wide variety of gaming with lots of cracks and hacks whereas Mac becomes a jailer which will tell you what games to play what to avoid maybe because of the guidelines issued by the company.
But what are we supposed to do with the guidelines when we can't even play our favorite game.

YES! Games are just another form of art. So what if they are commercially available on the market? I don't even need to mention other art forms that are commercially available.
To explain the my point I would like to mention games like Assassins Creed, God of War. These games are not just made directly on a computer machine. The characters, the BG's the story, all of these are designed by pure artists who know how to involve people in their story lines. Machines are just for the execution of the characters and everything else. It starts with Art.