Your mocking tone does not help the argument. The issue with zeroing
one's altimeter has nothing to do with units of measurement. One can
fly safely and proficiently using knots, meters per second, furlongs
per fortnight, etc. Flying with one's altimeter set to zero
simplifies one data point (height above ground at the departure field
for a given barometric pressure), which has a certain appeal to
neophytes, but complicates everything else from final glides to
spotting traffic.

The point about the Law of Primacy is not that QFE is "wrong" per se
(although its disadvantages should be obvious) but that, once taught,
it may be hard to unlearn. So why bother teaching it? Instructors
and club officers should be mindful of the problems it can cause.