As a mathematician and educator I was an early advocate of the metric system, and shared your complaint about cups and quarts, pints, teaspoons, etc. Then, in middle age, I started cooking and building things, and I discovered something remarkable. The old US version of the older Imperial system of measurements embodies some remarkable wisdom. The volumetric measures are actually binary; two tablespoons in an ounce, 8 ounces in a cup, double that for a pint, again for a quart, and twice more for a gallon. The length measures allow for easy divisibility (12 is an abundant number, unlike 10) making it possible to easily design and build almost anything on a human scale without resorting to decimal approximations. I now think very differently: the old system isn't old-fashioned and dumb, it is old-fashioned and full of subtle sophistication. I think people are right to resist having it taken away from them. An educated populace should have no trouble learning it and the SI system, and using whichever is most appropriate for the task at hand.