Whatever happened to the mamaloshen?

Looking through my collection of books and commentaries on Pirkei Avot, it suddenly dawned on me that something might be missing.  Not every commentary on Avot has been written in Hebrew. The Rambam's Pirush Mishnayot was originally penned in Arabic: the version we learn today is the translation of the ibn Tibon family, and Rabbi Yitzchak Magriso's Me'am Lo'ez on Avot was written in Ladino -- but in all the years I've been learning Avot I can't recall ever seeing any mention of a major (or even, for that matter, minor) commentary that was first written or published in Yiddish. 

Though I neither speak nor read Yiddish, I am curious to seek an explanation. There are many possibilities. For instance:

• There are no commentaries in Yiddish;
• There are commentaries in Yiddish but these add nothing to pre-existing commentaries in Hebrew and have therefore not been cited or discussed by later writers;
• Yiddish commentaries that were of interest or merit have already been translated into Hebrew and published in Hebrew but without any obvious reference to the fact that they were first published in Yiddish;
• Commentaries in Yiddish did exist but were all lost or forgotten during the Holocaust and the persecution of Jewish populations in the years leading up to it;
• I have seen footnoted references to such commentaries in Hebrew format but did not know that they were originally written in Yiddish.

My parents' generation spoke Yiddish and considered it the Queen of Languages. Its cadences, colourful expressions and egregious theft of words from other languages made it a source of pleasure, amusement and nostalgia for them -- and for very many it was their life membership badge, proof of their true Jewish status, long after any vestiges of religious practice had been cast off. It was the only language in which one could say "Oy!!, "Oy! Oy!" or "Oy! Oy! Oy!" with any degree of sincere conviction. Did this somehow disqualify it as a language fit for commentaries on Pirkei Avot?

Readers' comments are invited -- as are any references to works that fit the description above.