The Anglo concertina is actually a little better for lefties. So is, allegedly, the typewriter keyboard (E, T, and A comprise about 30% of English text.)
You'd be surprised how much around you has a right-handed bias without you ever noticing. For example, how many people ever realize that ATMs are right-handed? They all have the screen on the left side, with the card slot on the right. And if buttons are along the screen (or on the screen,) they will be in a column along the right edge. The assumption is that if you ever touch the thing, it will be with your right hand.
I was at a meeting where a signup sheet was passed around, and one employee remarked, "holy crap, this is a left-handed pen!" It was indeed a left-handed pen, but all of the righties thought he was either joking or crazy. After all, how can a ball-point pen be left-handed or right-handed?
It was fun watching people puzzle over the thing and not figure out what he meant. Those silly people who run the world just don't get it, eh?
Caj