I don't think that's correct.
First of all, there are two button mice for Macs, too, so it's not a general Mac problem. And even with the single-button mouse, you should be able to right-click in our games. From what I have researched, Ctrl+click is a substitute for right click. And if you own a "Magic Mouse" you should be able to right click just like you would do with a two-button mouse (if configured correctly). I asked someone who also works with the game engine we used - he had never had any problems with his Magic Mouse.
Right mouse click functions are very common in games, I believe.