As 95 percent of the world is now metric, there still remains one developed country that has not yet adopted the metric system as their official system of units, the United States.
American schoolchildren currently are taught two systems: the metric system and the U.S. customary system. The former uses base units of 10 for everything, while the latter is completely inconsistent. Why must they have to learn both when one of them is so much simpler and thus easier to use?
Most countries have adopted the metric system officially throughout the 20th century. We remain behind the rest of the world by still using customary units. Why should we wait any longer? It's in our best interests to join the rest of the world, and use a less-complicated, more-accurate, universal system of units!