The war doesn't end and doesn't achieve anything because Israel rightly refuses to prosecute the war with maximum aggressiveness, since doing so would eliminate Hamas at the cost of too many civilian casualties; and Hamas lacks the capability to achieve military victory. So militarily, should Israel surrender and let Hamas win, or should Israel finish Hamas even though doing so would be a civilian bloodbath?
Regardless of the inefficacies of the military conflict, there has not been a lack of negotiation attempts. Hamas doesn't merely reject Israeli proposals, but those of the UN, and even those of Arab governments-- as for example, the multiple cease-fire attempts in this conflict that Israel has accepted and Hamas has rejected. At other times, various fair and reasonable proposals have been made, and Hamas has rejected them all.
The starting point of Hamas has always been that the State of Israel has no right to exist, and it must be destroyed, with all Jews living in it either killed, expelled, or condemned to second-class status under the draconian rule of Hamas. That is their starting point: if they do not change that starting point, how are negotiations supposed to proceed?