> * It was started by a German living in Germany while a student at a German university
Even at the time, he wasn't a sole contributor. He posted to a Usenet board and gathered interest of a multinational group before commencing. Today, it's even harder to make that argument considering the minority of KWin, Plasma, etc commits come from Germans (or even Western Europeans).
> * Its current-day non-profit backing org[1] - which owns the KDE trademark and represents it in legal matters - is headquartered in Berlin.
Sure, KDE EV is German. And both the Linux Foundation and FSF are headquartered in the US...yet you would probably take umbrage with GNU/Linux being called "American" for that reason. You have to incorporate somewhere and it's probably going to be somewhere in North America or the EU.
Sure, its contributors are from all over, but
* It was started by a German living in Germany while a student at a German university
* Its current-day non-profit backing org[1] - which owns the KDE trademark and represents it in legal matters - is headquartered in Berlin.
[1]: https://ev.kde.org