The Arabs have no reason. They fled Israel in 1948 so as to give the Arab armies free rein to kill the Jews. Jordan was to be the Arab part of Palestine, not half of the Jewish part. Afterwards the Jews just didn't allow all of them back. The Arabs who stayed are full citizens of Israel and have more freedoms than Arabs in any Arab country. The rest of the Arabs chose to leave the Palestinian Arabs in squalid camps because they 1, don't like them much and 2, want them to suffer so their suffering can be, falsely, blamed on Israel. If Hamas actually cared about the people in Gaza they would quit firing rockets into Israel, using women and children as human shields, quit demanding that all Jews just leave or die.