Why teach about the Holocaust?

§801 of NYS Education Law that requires school districts to teach about the Holocaust.
"In order to promote a spirit of patriotic and civic service and obligation and to foster in the children of the state moral and intellectual qualities which are essential in preparing to meet the obligations of citizenship …, the regents of The University of the State of New York shall prescribe courses of instruction in patriotism, citizenship, and human rights issues, with particular attention to the study of the inhumanity of genocide, slavery (including the freedom trail and underground railroad), the Holocaust, and the mass starvation in Ireland from 1845 to 1850, to be maintained and followed in all the schools of the state. The boards of education and trustees of the several cities and school districts of the state shall require instruction to be given in such courses, by the teachers employed in the schools therein. All pupils attending such schools, over the age of eight years, shall attend upon such instruction."