Metric is a product of the French Revolution, as well as decimal currency like cents. Some decimalization from the French Revolution didn’t catch on widely, like gradians for measuring angles or decimal minutes, hours, and weeks. The imperial units were standardized by various monarchies (hence the name).
If the pole is entering the portal at the rate of 60 miles per hour, it must exit the portal at the same rate. After a minute, 1 mile of pole has entered the portal, and 1 mile has exited it. If it exits more slowly than it enters, where is the missing part of the pole?