Why have some historians reject the labels bc and ad as labels for periods in world history

Well, if you didn't know B.C stands for Before Christ which is using mainly by Christians and A.D stands for Anno Diomini or the Year of the Lord which again, is used by Christians. They prefer to use B.C.E (Before Common Era) and CE (Common Era) as it doesn't show anything to do with religion. This is what I think.

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;