The requirement that the tag value be a name or just a word was added by one user in Sep 2021 https://wiki.openstreetmap.org/w/index.php?title=Key%3Aname%3Aetymology&diff=prev&oldid=2200202 with (as far as I can tell) no discussion on the forum or the tagging mail list.

As it currently stands it makes the tag useless because all you get is stuff like John Smith Street name:etymology= John Smith. It doesn't tell you anything. When I've used it I've put in a short bibliographic sketch that points out who it is and why they are important enough to have something named after them eg https://www.openstreetmap.org/way/436816913

Maybe this debate should move to tagging on the forum?