Some people are more comfortable with mouse inversion, that is also my case; I read years ago somewhere that it is subjective and depends on how we "see" the scene in our brain, like 1st person or projected 3rd person (or something similar, don't take my words to the letter) anyway the number of people that would find games without mouse inversion next to unplayable is very high, therefore adding the option makes sense, and many games in fact have it.
I got used to normal look controls with practice but lots of 2005ish console games have inverted controls as defaults. I started a playthrough of The Legend of Zelda: Twilight Princess on Gamecube to find that is has inverted left/right camera controls as the default. Also, GoldenEye 007 for the N64 has inverted up/down camera controls (if I remember correctly). If you're a certain age, you lived through a time when there was not an accepted default control scheme so console games just picked defaults and moved on. We got used to those defaults. There was a period of time where choice of selection of up/down inversion was seen as a must-have to even play a game (multiplayer split screen) and zero discussion or complaints would arise over 2-3 minutes of everyone (all 4 of us) setting their controls after every console reset. Eventually non-inverted controls became the accepted default. This likely happened during a time that many of us gamed less so we might not have the muscle memory of relearning the new defaults. That's my experience on the whole thing anyway.
i always thought it was people of a certain age who required inversion (i include myself here) because the first 3d games were flight sims, so pulling back on stick/down goes up etc.
At least for me, I've always associated preferring mouse inversion with growing up handling BB guns. When you're lifting a rifle up, you are pulling back/contracting on the right arm. When aiming, to go up you nudge the right hand down, or nudge up to point down.
I could see this. Like obviously I live first person, and when I want to look up I pull my head back, to look down I push my head forward. Similarly I expect pushing my mouse forward (up) to look down and pulling my mouse back (down) to look up.
If I grab your head and pull back you would be looking at the ceiling. If I pushed your head forwards you would be looking at the floor. This is how mice should work. Touch devices screwed that up and are heresy.
Here's the `invert mouse` setting from Quake2[1], though, I know for certain that Duke3D and Doom had the same option. I feel like every FPS I've ever played has had it as an option.
Now, to be judgemental, anyone who enables the invert option is an obvious psychopath. Although, to be fair, everyone thinks I'm a psychopath for using Mouse2 for Forward.
"Shearing" was added for up-down look in Heretic, for the non-Doom engine descendants Duke Nukem 3D and Rise of The Triad supported it as well. I don't remember if it could be bound to mouse movement in any of these games.
They were bound to keys for the DOS versions from memory. Forget when the mouse look was supported but the view was highly distorted so mostly useless until later ports enabled proper 3d rendering.
