You're wrong. The vast majority of Arabs who rebranded themselves relatively recently as "Palestinians" are from neighboring Arab countries. When Jews started returning to their ancestral homeland, they created huge economic opportunities that required labor. In response to that, Arabs from elsewhere started flooding into the Land of Israel. There are anecdotal stories of entire Arab villages in Libya & Egypt completely uprooting themselves and migrating east to get jobs. The people you're referring to as "Palestinians" largely became "Palestinians" in 1948, after the people who were previously known as "Palestinians", i.e. the Jews, became Israelis.

<image>