RealFlight has a very small market (RC Pilots who want to learn and play on a computer). Now, I think that the Mac has about 2 to 3% of home computer sales. If I were them, I would not put the money into porting the system to Mac (keeping in mind that they developed to Microsoft DirectX in the first place). It would be too expensive, and the cost would be so high per user that you could get a used car for it.

I sympathize. Maybe they should port it to Linux. That way, PC users could use it, and Macs that run OSX will have a chance as well. Now we have raised the market share to about 5%. What will the future bring? I think that you will see Linux gain more market share over the next 5 years, and it will out-pace Apple. When corporations are ready to put forth the up-front money to train their users on Linux, you will see even more share go to Linux in the home.