It is also, like many things in hardware, a software problem. The purpose of a keyboard is to interact with software. And that software is biased towards certain layouts. It is hard to change the layout too much without quickly becoming a niche product. Add to that the barrier to entry to making a hardware product is still quite high, and relatively costly.
The DataHand was a new interesting “keyboard” design in the 1990’s, about 25 years ago.
https://en.m.wikipedia.org/wiki/DataHand
Btw, Xahlee has a great article on keyboard switches:
http://xahlee.info/kbd/keyboard_switch_mechanisms.html