Being the majority, right handed people really screwed themselves over with the design of the keyboard and mouse. In the past there was no mouse, so the navigation cluster and numpad were put on the right. Now that we have the mouse, why are these keys not moved to the left?
The way keyboards are designed currently really favors people who use a mouse on the left side.
I use the mouse with my right hand, and even with a TKL keyboard, it is so awkard to have to move my left hand all the way to the right just to use the navigation cluster (and the keys above it) and the mouse at the same time.
People are resorting to small form factor keyboards to avoid this problem, at the cost of losing functionality. And for small keyboards that still have the arrow cluster, they are still put on the right.
The only way to fix this is to get a smaller form factor keyboard and a separate numpad.