Problem with a foot is, that it creates a reference, to well a human foot. But my feet are 11" whereas my gfs feet are 9.4" and my fathers feet are 12".

So four foot for my gf would be three foot for my dad. That is a terribly inaccurate references.

We used to have the same thing for cloth, where the length was measured with your underarm. Guess the shorter traders got rich off it.