(Yet another) Try at fixing the Fighter

[Ilja]

Seriously? What is the reasoning behind that?

The reason would probably be that you can have different feet on different steps, easing balance. Try it for yourself - get a couple of beers, then try walking the length of a single step without tripping. It would require at least a bit of concentration. Try walking up the stair. Shouldn't be a problem.

 

[Ashtagon]

If you momentarily lose your footing on a flight of steps, you can easily put your foot down on the next step. if you momentarily lose your footing on a narrow plank of wood bridging a chasm, there's no handy piece of wood next to it.