Yes, I am left-handed, and I learned from a very early age how to swap the left and right mouse buttons as I use the mouse in my left hand, and the standard configuration of "wasd" is rather inconvenient for me.
I don't really understand the left-handed problem. You might be fuming right now but hear me out.
I've known plenty of righty people that adapts to right-click being the main click because at some point the left-click button starts acting up. Then they just keep going that way on every computer they subsequently own. (it's slightly confusing to use their computers. For 10 minutes, then you "get" it)
I knew one guy that became a lefty mouse user(and skilled FPS player) because he was too lazy to rearrange the mouse and keyboard every time his lefty brother used their shared computer(90's).
Programs like Blender used to have right-click as selection by default. It's nice enough to ask you know when first starting it.
"But you don't know our plight!" Ok, listen, everyone here has used emulator and if you used them back in the past to play Super Metroid, Mario, Ninja Gaiden or whatever then you most likely used the directional arrows on the keyboard as the d-pad and had all the buttons on the left hand (shift, ctrl, z, c whatever). The layout was the mirror image of a joypad. Any right handed person here remember really struggling or never being able to adapt to that? I don't, I never even considered that I was supposedly using a "left handed" setup until some years ago.
Do lefty people have trouble playing Mario on a normal joypad? Probably not.
I don't remember my point and I refuse to read my post, but I understand the plight of you people because of all the right-handed "ergonomic" mice, with those there's not even a choice. Then there's advanced "bi" mice that no one is happy with. Yeah.