You are correct that they overruled a case - as they do from time to time, like when they overruled Dred Scott and Plessy v. Ferguson. But to throw out the incorporation doctrine would be to throw out every case that has addressed the issue of whether the states have to comply with the Bill of Rights in the last 80 years.
Just so we are clear here - you do not believe that the conduct of state government is limited by the Bill of Rights.
Crystal clear. You believe that the Bill of Rights mandates that states establish non-religion.