I already explained, but I'll elaborate. Zionism was originally a predominantly peaceable strategy of buying land from its owners; the Palestinians often did not own the land they lived on, and there was a lot of inexpensive land in then-undesirable areas, so it was an effective strategy that led to a significant demographic change.

But that didn't prevent the same kind of reactionary attitude from the Palestinians that you find in the U.S. Right today regarding immigrants.