I think all these Gaming on the Mac or developed on the Mac, all happen when Steve Jobs wasn't in Apple.
I wonder if Steve Jobs was ever a gamer. He worked in Atari, that should means something? It seems right after Steve Jobs came back the one thing he decide not to focus on is gaming. And ever since then Apple hasn't been in gaming community at all.
Apple now, is possibly the largest Gaming platform by revenue, most of those App Store revenue, my bet is that 80%+ are from gaming. But this wasn't because Apple thought Gaming was important, there simply had the Software infrastructure and best hardware in place. I wish they could do the same for Mac, but then again, I dont see Apple cares about gaming at all.