heres another why:
we all said naaseh v nishmah
why did we need to say nishmah (we will hear what You want us to do)
obviously we cant do unless we first hear what to do, nishmah is logically implied completely by naaseh
it means we will hear from You what to do, and we will do it even if we dont understand it.
we will hear from You, who told it to Moshe, then to the elders, etc from father to son, from Rebbi to Talmid. not from our own understanding alone.
if You tell us, from this Mesorah, as explained by the poskim who have received and given over the Mesorah, that we may not drive on Shabbos, then we may not drive on Shabbos, even though it seems to us to be okay in order to allow Yidden to go to Shul on Shabbos, even if it seems to be imperative to us in order to preserve the Jewish People. nevertheless we will do only what You tell us is permitted and not follow our crippled, blinded logic.
this has always been the way of the Jewish people, until refarm raised its cancerous head a couple of hundred years ago in order that we should be like the goyim, not a unique beloved people of Hashem, hated by the nations.
the conservitive, reacting to this evil, perpetrated the same blind mistake, albeit for more benign reasons.
they are all outside the Mesorah, they have nothing to do with the life and purpose of Hashem’s people
i dont know much (although i know enough) about all the other made-up, so called branches and sub-branches of the ONE nation of Hashem.