I wonder if it's because of the 1990s-onward resurgence of attempting to reclaim Celtic culture/language, and a lot of white Americans not thinking it's a particularly legit language because, you know, it's supposed to be dead and all the Irish people assimilated and speaking English and stuff.

(I recently saw a post fly by on one of my social media feeds about someone teaching their kids Yiddish instead of Hebrew who was getting a lot of crap from fellow Jews for it.)

The husband telling her she's white and should basically get over it smacks really hard of both not wanting LW and child to have something he doesn't AND not thinking her language is legit, that it's just some weird pecadillo that she has.