So what if Yiddish is a pidgeon of German with large chunks of Hebrew, and smaller chunks of Aramaic, Old French and miscellaneous Slavic languages throw in. English is also a pidgeon of German with large chunks of Hebrew, a few traces of various Celtic dialects and misc. pieces from other languages thrown in for flavoring (including many Hebrew and Yiddish words).
The point is that (if you are Ashkenazi), Yiddish is our pidgeon, and no one else’s. It is the language our ancestors spoke for 800 years. While all our important literary and scholarly works were in Hebrew (similarly, almost nothing of significance was written in English for 400 years after the Norman conquest, and serious scholarship didn’t beging to appear in English until the end of the 18th century), but Yiddish (or for the Anglo-Americans, English) was the language people ate and breathed in. It is the language the best reflects our cultural and religious traditions. This is the reason so many Yiddish words entered our English disalect as well as modern Hebrew.