For many years, Yiddish was considered the preserve of the older generation, the generatiaon that came from the heim, from Eastern and Central Europe. For many, speaking the language also conjured up negative feelings associated with the shtetls of Eastern Europe and with the Holocaust.
In the early years of the state, the official line was to nurture Hebrew as the language of the proud young Jewish homeland, and all foreign tongues were frowned upon. Part of the government’s drive to maintain the revival of Hebrew was to impose taxes on all forms of entertainment presented in a foreign language. That led to a decline in the use of Yiddish as an everyday vehicle of speech, and some Yiddish entertainers left the country.