There is no logical reason moral responsibility requires free will. Therefore free will is not necessary for moral responsibility and all the literature saying it does is incoherent. To the flames.
People have blamed each other for many reasons throughout history. The idea that we should only blame them if they made a free will choice is a recent development that was a result of a lot of discussion until we finally settled on this current criteria. Saying we should only hold people morally responsible if they have made a free will choice is not the same thing as saying they really are morally responsible.