Fair enough. I learned old system, but needed metric for the sciences. I'm not as fluent as I would like to be (darn US educational system), but I manage.
I never could understand it myself. I remember more than 40 years ago, there was a big push towards metric, "Think Metric" and all that. The country seemed to moving in that direction, and then, it suddenly stopped.
I don't recall it being any real kind of significant political issue one way or the other, so there was no obvious reason for the U.S. to inexplicably abandon the idea of switching to metric.
If there had been massive public protests against switching to metric, then I could see, but absent that, it makes zero sense whatsoever.