The reluctance of Hamas's "military wing"—a misnomer for the more extreme elements of its extremist leadership—to accept the cease-fire designed by Egypt is, well, logical. Let's admit it. They do not wish to accept defeat, and the Egyptian terms are a defeat for Hamas.
There were a few stated "war aims" for Hamas, and the first was freeing terrorists who were let out of prison in exchange for the kidnapped Gilad Shalit but recently re-arrested by Israel. That's not in the Egyptian proposal. Second, Hamas also called for opening the passages to Gaza, and the Egyptians have promised to do that. But Hamas knows that it is at the tender mercies of Gen. (now President) Sisi and the Egyptian army, which hates them and the entire Muslim Brotherhood. Once the "international community" turns its attention elsewhere, those open passages will get clogged once again.
There is an alternative assessment, and some on the right in Israel are calling the Egyptian proposal for a cease-fire an Israeli defeat and Hamas victory. Two members of Israel's security cabinet voted against accepting the proposed terms. They argue that Hamas sent millions of Israelis cowering in shelters for days, while escaping punishment and reviving Hamas's fortunes.