The Palestinians have stronger genetic lineage to the original inhabitants than the Eastern Europeans calling themselves Jews. There were conversions and an influx of Muslims over the centuries, but the original peasant farmers never left.
What about Egyptians calling themselves "palestinians" - like Yasser Arafat?
Most of the Jews were either killed or dragged to other countries, but there has been a continuous presence of Jews. A Jew is always a Jew, whether in Israel or dispersed by the Nations (Rome, Babylonia, Persia, etc.)