I have six or seven 'what to name the baby' books, the Oxford dictionary of names, and a fabulous tome that's 26 languages in simultaneous translation - French, German, all the European majors, plus Esperanto, Arabic, Hebrew, Chinese, Japanese, and so on.
Yiddish, originally, in Eastern Europe was considered the language of children, of the illiterate, of women. And 500 years later, by the 19th century, by the 18th century, writers realized that, in order to communicate with the masses, they could no longer write in Hebrew. They needed to write in Yiddish, the language of the population.