Then even if it were done there's next to no real advantage. The amount of Mac / Linux gamers is extremely small so there's no real gain at all...
This is not true. I have read lots of sales reports of indie devs and they often make much more money on Mac. The mac demos have a better converion rate (trial to sales conversion). And there is almost no competition on the Mac platform.
The Mac games-market is too small for the big developers, but it is a very good market for small developers. That is the reason why many devs at GarageGames fought for Mac support.
But this is only important to business developers. If you want to have fun as a hobby user, then this is not an issue.
