Avirah, your sytem does not work in the rischa deoraysa of yeshiva. Kol Hakovod to coffee addict for bringing back intelligent discussions to the YWN CR! And thank you, mods, for letting these discussions through.
When someone asks a good question, you can’t just say “Mesorah”! You need to back up your point from a source in shas and poskim. His whole question is how did that mesorah develop? We have always had women in Klal Yisrael who were not watching children.
To say it is not an ikar for women is also not an answer. No one said it is an ikar. The question is if there is not such a high level of difficulty why is not more commonly done? For a man to daven vasikin is also not an ikar but we don’t say “man should not daven vasikin bec. his ikar is learning Torah”