Well you had a point and kinda lost it, the English speaking judo community absolutely does use Judoka. It's not the English speakers that don't use it it's your dojo that doesn't. Even r/judo calls them Judoka in the sub description, your wrong if you think no English speakers or Americans use Judoka. I even found a fox news article that uses Judoka, it's absolutely used in America.

https://en.m.wikipedia.org/wiki/Judo https://www.ijf.org/judoka https://www.researchgate.net/publication/259811980_Judo_high_level_competitions_injuries https://www.google.com/amp/s/www.espn.com/olympics/story/_/id/31888239/judoka-nora-gjakova-wins-gold-women-57-kilogram-mourning-day-kosovo%3fplatform=amp https://www.google.com/amp/s/www.foxnews.com/sports/israeli-judoka-tohar-butbul-olympics-run-political-controversy.amp