@OP:
By gaming on Mac, you gain the ability of not booting into windows ( if that bothers you ). And it also gives the developer relief that customers are buying his product on this platform so maybe they will put out more games in future.
Thats it.
@People saying PC gaming is Dead :
Firstly, I admit PC gaming does not have its stranglehold reminiscent of the 90s.
But, that does not equate to 'dying' or being 'unconscious' for that matter. Nowhere near it. Granted its a second choice platform now to release/develop games for behind consoles, people citing nonsense figures of sales irks me. I mean 98 million $ in sales money for PC in a year ?? Thats like what Blizzard makes in 3 months ! If you count money generated by MMOs alone, you would think PC gaming is teh shizzle.
Anyways, there is a reason why that stranglehold isn't there.
The late 80s and entire 90s were the time PC gaming was seen as a niche market full of nerds and 'computer people' who liked to spend their free time on the computer again.
The consoles like NES, N64, Amiga, etc were kind of like a 'family time' thing where kids gathered to have some fun for a while and then get back to playing outside or doing other things. It was seen as a casual thing that the kids ( sometimes adults ) engage in occasionally.
The real men played on PC

....Requiring hardware/software knowledge far beyond the scope of a normal individual, it was a catalyst for early 90s developers to break new grounds and create genre defining games signaling the growth of the industry. Dev work was done '
for the pc, on the pc and by pc geeks'. Console games were ports of PC versions. PC penetration in homes was exponentially growing and outnumbered the consoles combined. That increased the number of people who knew atleast how to operate a system on a very basic level.
But as the industry grew, the focus from 'the hardcore guy' as customer shifted to a more casual ' Average Joe/Jane' who didn't want the hassle of trying to figure out why the game needs certain drivers to work and why a power supply churning out 300W doesn't power their system well. So, consoles began to be adopted in households more than PC for the sole purpose of gaming and the PC took a backseat as the 'office machine'. This resulted in developers having to chose between a larger audience who were willing to pay extra 30% for the game to work 'straight after putting the dvd in' or the people who would buy handful of games, be put off by not knowing how to get the full potential of it and the illusion of requiring latest hardware to run it and pirate others.
Naturally, the first option was more viable economically and thus the new motto of development was '
for consoles, on pc, by pc geeks'.
Of course the cost of development is higher on consoles in most cases but it doesn't justify the prices still to an extent imo. With the advent of HDTVs, the whole 'entertainment system' was consisting of a console, HDTV, 5.1 speakers, some games / movies / music collection and voila !! A hub for the family.
I am on old school guy who loves his mouse/keyboard combo ( and fyi, I am not a die hard FPS fan ), thinks controllers are best suited for platformers, and laments the fact that the industry base is dumbed down and the major players have to play to them first to make money and then focus on PC.
Kinda like what Mac games development used to be in its hayday. Now it has taken a backseat ( except on iPhone ) . Just like PC gaming has taken a backseat to Console. But its a backseat, its not like the driver has thrown them outside the car to die.
As it stands, consoles are driving the industry with the PC arguing which turn to take from the backseat while the Mac is in the trunk trying to remember whats all the shouting about through a peep hole the size of an apple.