Some autoloaders vent gas back into my face when firing. I don't like that. Also, I've had a couple of pierced primers and one split case. Not an issue with a right-handed shooter, but it left me feeling like Wile E. Coyote. Many pistols also eject into my face.
I can hold and operate a gun right handed, but hitting anything specific requires the left eye. I've seen cross-over shooters, but that's just awkward for me.