How? I can see no way this argument can be used against the metric system.
The abacus method is a fundamentally different way of doing arithmetic, that's why the abacus guy didn't know numbers. But metric and non-metric are fundamentally similar, only metric is much easier, gets out of the way, and lets you think about the quantities instead of thinking about factors.
That was sarcasm. I was surprised that he knew those factoids about feet and inches, which eventually gave him an edge in the competition. He won because of them. And that was the only benefit he ever got out of not using the metric system.
The abacus method is a fundamentally different way of doing arithmetic, that's why the abacus guy didn't know numbers. But metric and non-metric are fundamentally similar, only metric is much easier, gets out of the way, and lets you think about the quantities instead of thinking about factors.