Not exactly, since there is only one constant to convert (not many units) and the conversion factor is very straightforward (2 pi = 1 tau instead of 39.37 inche

Not exactly, since there is only one constant to convert (not many units) and the conversion factor is very straightforward (2 pi = 1 tau instead of 39.37 inches = 1 meter). But yes in that many people would have to change their ways.