He wants to SELL his game to Mac users, not become a Mac user.. surely you can see the difference?
Very good point actually. It's more than the cost of a Mac, it's devoting enough time to learning it so that you can properly deal with support issues. If someone emails me with an obscure comment like "If I do the thing where the thing bounces, it stops working and my internet stops." I have a fair idea what they might be talking about and I can deal with it. In order to be that conversant with Mac support issues, it would take a considerable amount of time.