Al-Zahar makes it clear that, for Hamas, peace will only be possible when Israel no longer exists:-
A "peace process" with Palestinians cannot take even its first tiny step until Israel first withdraws to the borders of 1967; dismantles all settlements; removes all soldiers from Gaza and the West Bank; repudiates its illegal annexation of Jerusalem; releases all prisoners; and ends its blockade of our international borders, our coastline and our airspace permanently. This would provide the starting point for just negotiations and would lay the groundwork for the return of millions of refugees. Given what we have lost, it is the only basis by which we can start to be whole again.When the only basis for peace with Hamas is the destruction of Israel it's little wonder the Israelis see no point in negotiating with them.
I've said it before but it's worth saying again because some people still don't seem to get it. Hamas's dedication to the destruction of Israel is not some bargaining position that can be negotiated away by wily diplomacy, it's a central commitment and Hamas are hell bent on violence to achieve it.