Because they lost at least 3 ****ing wars. Once upon a time, used to be common courtesy that when you lost a few wars, you packed your **** up and went somewhere else. You admitted you were bested in a fight for land, as surely your ancestors had to have bested someone to get it to begin with, and moved on.
You would think based on Palestinian apologists that they were the first ethnic group in history to have someone conquer and drive them out. I don't know what the hell makes Palestinians so special.
And yes. The Palestinians should just name the price for whatever it is they believe they own in that part of the world so Israel can just buy them out and they can go somewhere and shut the **** up about this whole thing.