They advocate it because Israel was built on the ethnic cleansing of 500 Palestinian villages. Of course we know that if someone arrived from another continent and put a gun to your head and forced you out your home, you'd accept it; after all, you're not a hypocrite. But that region will never forget or accept that.
“If I were an Arab leader, I would never sign an agreement with Israel. It is normal; we have taken their country. It is true God promised it to us, but how could that interest them? Our God is not theirs. There has been Anti - Semitism, the Nazis, Hitler, Auschwitz, but was that their fault ? They see but one thing: we have come and we have stolen their country. Why would they accept that?”
-- David Ben Gurion, founder and first Prime Minister of Israel
And I don't know what you're referring to with "liberated". It was the Arabs/Muslims who liberated the land in the 7th century and allowed Jews to return to Jerusalem. Jews had been banned from that city for 500 years by the Romans/Byzantines.