The kids are marching, as they beg to have their rights and freedoms taken from them. They are marching for TOTALITARIAN control against themselves. They dont know that when a government removes guns from the home, eventually only the government will have guns. Once totalitarianism succeeds in removing firearms from the homes, loss of freedoms soon follow. The atrocities of the Third Reich were made possible by gun confiscation laws specifically against Jews years before the Jewish removals began. The 250 million deaths caused BY TOTALITARIAN governments in the 20th century were facilitated by first disarming the public. Disarmament of individuals is one of many steps toward complete control of the people. These kids are pleading to be subjects rather than citizens.
They don't know any better, which is why they should stay in school, preferably a non government school.