The hardware is great but the developers don't care about the platform for games. Many of the games you'll see for Mac are from films that Pixar did (Wall-E, the Incredibles).
And Homeworld 2, but only on OLD OLD systems. This makes me sad.
Ah I see your point. They have made the move to non-discrete graphics for their Mac Mini systems as Intel's offerings have improved significantly, but my MacBook has an nVidia 650M in it I think, which does me alright when I reboot to Windows on it.
But then again, I am not really playing modern games so am not really stressing it that much; (having said that, the fans do go mental in it).
I wonder whether it is a vicious circle for gaming on the Mac? Nobody buys a Mac to game on because there's no games on the platform, so developers don't write for Macs because nobody plays games on them etc. etc. etc.
At least that is one of the reasons I am yet to buy one.