Why do some folks want to kill all Jews for killing Jesus even though he was a Jew himself, Romans did it, he needed to die for our sins anyway and he preached peace and love? (please, no answers that basically just say, "Because some folks are dumb)
Probably because they want someone to hate and are blind to the most central tenets of their religion.
Jewish deicide is a historic belief among some in Christianity that Jewish people as a whole were responsible for the death of Jesus. The antisemitic slur "Christ-killer" was used by mobs to incite violence against Jews and contributed to many centuries of pogroms (an organized massacre of a particular ethnic group), the murder of Jews during the Crusades, the Spanish Inquisition and the Holocaust.
In the catechism produced by the Council of Trent, the Catholic Church affirmed that the collectivity of sinful humanity was responsible for the death of Jesus, not only the Jews. In the deliberations of the Second Vatican Council (1962–1965), the Roman Catholic Church under Pope Paul VI repudiated belief in collective Jewish guilt for the crucifixion of Jesus. It declared that the accusation could not be made "against all the Jews, without distinction, then alive, nor against the Jews of today".
Jews have been punch bags for almost everybody for eons and now it is a fashion. People like their daily dose of hatred for their failures and seek comfort in other's misfortune?