All Arabs must be the same to you, right? What does 20 other Arab nations have to do with Palestinians? Palestinians are distinct than Egyptians, Syrians, Jordanians, etc. The Palestinian people don't even have a country.
Like a previous poster mentioned, it's not the fact that Israel has a country that bothers them, it's the location. I believe Uganda was one option that the UN considered in the 1940s to establish the Jewish state. I bet you Israel would live in peace today if the country ended up there.