Lol what. If British cooks were routinely mocked and bullied for mispronouncing foreign words, then Delia Smith would have no career, everyone who has ever mangled chorizo, ciabatta, or bouillabaisse would be unemployed, and that Bake Off episode about churros would be banned from being aired.
Also, don't try to make ignorance/indifference to foreign pronunciations a class thing, Jack - years ago Top Chef had Toby Young on as a guest judge and he argued with the Americans about how to pronounce paella (spoiler alert: he was wrong) and he is posh as duck.