It's analogous to the current situation with the metric and imperial unit systems - yes, it would make sense to switch away from imperial units, but it would require many people to fundamentally change how they think about distance, volume, speed, etc. (or time, in the case of the calendar).

Although in that case, we sort of have a wrapper, in that many labels list both types of units, but I tend to just look at the unit that I know, and haven't built up a correspondence between the two, so that doesn't really help adoption.