Metric measuring systems are superior in almost every use case, with the exception, I think, of how temperature feels to us. As arbitrary as Fahrenheit seems, it does seem like a more natural scale to talk about the weather or body temp. The smaller units are nice for these purposes too. 0 being very cold and 100 being very hot feels less arbitrary than -18 and 38, even if celcius is more logical and easier to use for many other things.