The Toilet Door Mystery

A UK based friend recently remarked, "the US is vast, enormous resources and talent, the most powerful nation on earth. Yet for some reason they will not or cannot build a public toilet door that fits the opening." My reaction was, "What are you talking about?" He said, "the next time you are out and about here in the UK notice the stall doors in the public toilets. They start at the ceiling and end at the floor. In the US, they start at knee level and end at shoulder level. Why is that?"