“I don’t care what most frum people were doing 100 years ago”
You said otherwise in your earlier comment.
“The GRO disputed the shulchan aruch in his Psakim and other Poskin disputed the REMO at times. An acharon cannot dispute a rishon”
Rabbi, those two sentences are incompatible. The author of the S”A was a rishon. I presume you mean that usually an acharon does not dispute a rishon unless he has other rishonim to hang his hat on?
Yet there are even exceptions to that. What rishon ruled that women do not have to pray the shemoneh esrei, as the Magen Avraham rules? What rishon objected to the Radvaz’s paskening that the Ethiopian Jews were fully Jews with the status of Karaites? And I’m unaware of any support from anyone, rishon or acharon, for Rav Soloveitchik’s teaching gemara to women.
And Chas v’shalom we call the Magen Avraham or The Rov “fools”!