I don't see why you wouldn't, aside from the few negative responces you would get...
People use macs for media production because they come bundled with the stuff needed to do so, not because Macs are better than PCs at anything other than being completely idiot-proof. Now, considering in media design you don't need to be a computer wiz, being idiot proof is a plus, and so they are used. If you are a hardcore gamer, you most likely know a fair bit about computer and either: A) Aren't stupid enough to **** up your system, or B) Know how to fix it on the off chance that you do.
I, for example, have somewhere between 100-200 gigs of games, and the only time I have EVER had a problem on my PC was when I was trying to uninstall my linux partition.
Now, as for your "Macs can allow for gameplay and much more" statement: Before this Macs had almost 0 games (Now, we aren't talking about little flash games or downloadable games with no plot. We are talking about full fledged games like Sims 3 or Spore (Even though those two are aimed at casual gamers)), and there is not a single thing you can do with a mac that you cannot do with a Windows running computer. (Using Program XYZ is not what I mean here, I mean do specific functions.) Now, the same is becoming more and more true as time goes on for macs, but there is still a large gap, and one that is too large to be worthwhile for anyone who enjoys using computers for things such as programming.
Also why would you NOT want to be able to upgrade your computer? I mean games such as Crysis have already come out, and the scale will only keep going up from there (Though Crysis has not been properly surpassed yet, it WILL happen, and probably soon). And with a Mac, when Valve finally does give you a few games you will most likely: A) Get VERY few titles, or B) Need to get a whole new mac just to play them.
Now I, as a Windows user, can just pop in a new graphics card for MAYBE $100 if I sell my current one. and even that is most likely more than it will cost.