There's no reason they can't serve both with the age-old "difficulty" slider. Put it on "Arcade" and everything will fly like Starfox.
FSX has broken winds, abysmal performance issues and no dirty simple point and click SDK for updating airports with default content without having to download 47958734gbs of paid scenery.
FS9 is the last solid, working build, but every single airport is completely outdated (have fun updating them with clumsy SDKs) and it doesn't have my favorite absurdly expensive payware aircraft.
I resent enjoying flight simulators and wish I was satisfied by just looking at topless women and playing Street Fighter.