@mixture - you are wrong and ill-informed.
Did you know that Microsoft transferred Flight Simulator X to Lockheed-Martin, and that if you want to buy a copy now you must agree that is must be used for professional training purposes?
FSX is now called "Prepar3D" and owned by Lockheed Martin.
Microsoft now sell a product called "Flight", which is a much simpler simulator for home users.
Most professional flight simulators use FSX are the sim engine, with custom high quality scenery and third-party plugins for things like flight computers.