European vs American threading

There is one irritating difference between US and European audio. The standard threads on mic stands. I mean, why is this?
Most boom poles and the like use the Euro standard.

What's the difference? Charles Poynton lays it out for you.

"Europeans don’t use a metric (SI) thread but a 3/8‑inch diameter thread – British Standard Whitworth (BSW), 16 tpi. The Whitworth standard specifies a 55° flank angle (typical of pipe threads), not the 60° angle of the Unified Thread Standard (UTS) or the the ISO metric screw thread. Abbreviated: 3/8″-16.
Many microphones having 5/8‑inch mount are shipped with an adapter that screws into the 5/8‑inch (“American”) threaded hole, and offers a 3/8‑inch diameter (“European”) threaded hole. Colloquially, this is a 5/8″-27 to 3/8″-16 threaded adapter."