“clearly, they did not speak Loshon Hakodesh, even before the Churban.”
Wow Joseph – I was about to bring a passuk from Navi to say not like you but when I saw it I realized you may be onto something.
http://www.hebrewbooks.org/pdfpager.aspx?req=14263&st=&pgnum=381
“????? ????????? ???????? ????????? ?????????? ????? ?????? ??? ???????”
It looks like rov am during bayit rishon didn’t understand Aramaic (which I’m assuming was the lingua franca) but they did speak something called Yehudit or Jewish (the literal translation of Yiddish as well!) I have no idea what exactly this Yehudit language was but the fact they didn’t say call it lashon hakadosh perhaps fits very well into what your saying.