This reminds me of an argument about Word vs. WordPerfect many years ago. That particular argument kinda fizzled out when someone proclaimed "WordPerfect is better because it has larger letters!!!!" :rofl:
True story btw!
Actually, you are not far from what I was thinking. As with word processors, the process of picking which unit system to use is in many ways a market decision.
The US government hasn't asserted itself as forcefully as many other goverments; it's pretty much left up to a popularity. Drivers, of course, are forced to use imperial units on the roads, but in your private life you can use whatever you want. Many rulers come in both units.
NASA still uses imperial for many legacy programs (STS), but newer programs are increasingly using metric. The contractors who do space work prefer metric as well, and their young new-hired engineers all used metric in college.
So metric will eventually edge out imperial as time goes on. But imperial will stick around for those who feel more comfortable with it. Even in the UK people still measure their weight in "stone" and in literature "miles" is still more romantic than "kilometers".