That is bullshit. First of all, Hamas is a part of the Palestinian people, it is not apart from it. Second, Hamas was not the only group that was involved in the 10/7 attack. Look here:
October 7 Hamas-led attack on Israel
Under "Units Involved" you will see "
Palestinian Joint Operations Room" which coordinates operations between various factions. Then you have
the al-Qassam Brigades, Hamas
the al-Quds Brigades, Islamic Jihad
the al-Nasser Salah al-Deen Brigades, Popular Resistance Committees
the Abu Ali Mustafa Brigades, PFLP
the National Resistance Brigades, DFLP
the al-Ansar Brigades, remnants of Fatah
the Mujahideen Brigades
So contrary to your claim that it's just Hamas, groups from all over the Palestinian society participated - even those ideologically diametrically opposed to Hamas such as PFLP and DFLP, two Marxist-Leninist groups.