Palestinians use negotiations to gain whatever small advantages they can. The ultimate goal, as is plainly displayed on official Palestinian web sites and official documents, is the expulsion of all Jews from what the United Nations erroneously calls “Israel.”
Do read it all. The Palestinians seem to value the mere chance of killing Jews as far more important than building decent lives for themselves.
Why anybody actually believes we must solve the Palestinian question first, before tackling any other Middle East problem, is beyond me.