I know this option is, not usually but, sometimes overlooked during game development. For me personally, after using it for almost 20 years now, I am too old and too set in my ways to change :) Please don't forget about us minorities and our weird ways.
Sorry if this has been addressed. I searched the forums and came up with no hits.
Is this the same question as brought up by the OP in the Southpaw! thread?
https://www.pantheonmmo.com/content/forums/topic/10739/southpaw
I do not think is has anything to do with left or right handed. I am sure there are many reasons but when ever I see the option in games, I think of flight simulators.
Y axis is up and down, X axis is left and right. Invert means you press the stick in the opposite direction you want to look in. so up is down, down is up.
I can remember being in some game where the default setting was the reverse of what I 'intuitively' expected and it definitely was a nuisance to work with until I figured out how to change the setting. I hope VR includes it.
It also seems like a Quality of Life improvement that one would have difficulty arguing against, no matter how 'make it hard-core' one's point of view is. Hopefully it will be a trivial bit of coding to include.
You know it is not too late. Back in the day people used to use the number pad instead of the mouse and it definitely was more hard core.