1. There are probably more children speaking Yiddish as their first language now than any time in American history (be real, in the “good old days” before World War I, most immigrants made a serious effort to forget Yiddish along with all other aspects of Yiddishkeit).
2. Jews usually use a Jewish language for serious conversations, and Hebrew is probably less understood than Yiddish, and more importantly, it is now the language of a foreign country which implies disloyalty in using it at a public forum, whereas Yiddish is an ethnic language rather than a foreign country’s national language.