Since it is inconceivable from a theological point of view that Am Yisrael transgressed an issur d’oraiso for so long, the Bach came up with a way to deal with it. We did not pasken like the Bach, we simply accepted the Bach’s explanation.
WADR, that is not the way Klal Yisroel works. If the Bach held it was Assur, he would have said so. In fact, I remember going through that specific Bach, and do not remember any apologies offered.
It may be that Paskening like the Bach was a B’Dieved, but that Bach himself actually held what he claimed.