1) the genetic lineage predates the modern concept of a region called Palestine, and this argument is ridiculous because if I marry a Palestinian woman and have a kid, you're saying my kid isn't Palestinian enough to have any kind of birthright in Palestine.

2) the general idea is that people of that lineage -- having been repeatedly oppressed and kicked out of literally everywhere in Europe at least once over 1800+ years -- should return to that region and establish a nation-state in which they can live under a self-determined government.

Ethnic cleansing isn't inherent there.