@freemo Well, would you agree that 2 inches or even 5 cm is more intuitive than 50 mm? Many of the same reasons, I'd say.
One is a matter of scaling of error. If your perception of any unit is off by a bit, then the more of the unit that you stack up stacks up those errors too.
You might intuitively know about how big a cm is and about how big an inch is, but once you start stacking them, the errors add up.