alt Hacker NewsWhat is good about metric is that once you have a good feel for different lengths of mm, cm,meters and kilometres you don’t need to worry about things like “10 Super Bowl stadiums”. You can easily extrapolate what 27km2 means, it doesn’t have to “look like” anything.
That really isn't true. You in particular may be good at such extrapolation, but people as a rule are not. They need a concrete example to relate back to.