I'm speaking about the one-hand operability, which I then conclude must not be very important and obviously the market prefers something else.
I will only address this part:
> The market is optimizing for what consumers asked for
This is hopelessly naive. This is true in the same sense that butane rings in cigarettes is optimizing for "what consumers asked for" - more pleasant to smoke cigarettes. Consumers don't know what they want, they're fed whatever is going to make the most money by advertisers. And they will like it, because there is no other choice.
The market is not some perfectly rational machine. It is, often, a self-eating beast, concerned with it's own self-preservation to such a degree that it destroys itself. Had the Tobacco industry chilled, they wouldn't have been eviscerated by legislation. But no - they had to target children, they had to make the death sticks as addictive as possible. As if to put a bright flashing sign on themselves that says "look at me! Regulate me!"