On the face of it, I agree with your thinking and understand it very well.
We must remember, however, that this is a U.S. preclearance area, so the Americans must at least be given the opportunity to allow tourists or goods to enter their country. We are not living in a time when people can travel anywhere on the planet. The purpose is to accelerate the flow of goods and passengers between Canada and the United States.
The question ultimately is whether you...?