Having Played with PC since DOS 5.0... I must say this: Having the ability to INVERT your X+- Y+- Z+- & R+- is INVALUABLE. I can not even Recant the number of times I've had to 'fly backwards' because of an interface issue with my Game-controller & Drivers or Windows etc.
It takes only a 'few' minuets to add & Code such a check-box these days. Might as well give the End-User such 'seemingly unneeded' options ;) (Pro-Tip there!)
Besides, You never know when someone might show up with an Odd-ball gamepad from 1998! (;Þ
GLHF