I dont think the OP understands that for many Hebrew is the jewish Language of today and not Yiddish.
To the OP
For the most part the debate between Yiddish and Hebrew is about Zionism (not entirly, but a great deal)
Those who are more zionistic will lean more and more towards Hebrew and those who are less zionistic and anti-zionsitic will lean towards Yiddish
Also Yiddish is an Ashkenazic Language spoken by Jewish from Eastern Europe. Sephardic Jews , Jews from elsewhere did have their own language called Ladino (A Spanish Hebrew hybrid) but that has been mostly lost and they have adpoted Hebrew as their language