That's not obvious at all to me.
To me, it's obviously wrong.
We can hold both Palestinians and Israelis responsible for giving their support to leaders and policies that make things drastically worse for the others.
If you can't do that, those people can't have democracy as an organizing principle. They need to be organized and controlled by others until they can be held accountable for who they support.
If you are saying that Israel and Palestine need to be dismantled, put under a protectorship, and released again if and when its people are committed to peaceable measures, well, make a more concrete proposal and we can think about it.
If you are saying that the Palestinians need to be rescued from Hamas, because 99% of them don't want violence committed repeatedly against Israelis until Palestinians are in control again, or if they do they at least don't want it done the way Hamas did, then we can discuss how to rescue Palestinians from Hamas.
But you cannot excuse a people led by extremists from the support that they give to those extremists.
One can both understand that it is human nature to do something bad under certain circumstances, and also hold people responsible for doing that bad thing. It doesn't have to be either/or. You can try to improve conditions and also insist that people act well or suffer consequences, up to and including death if there is no other way to prevent them from causing great harm.
It's very appropriate to be sad when such things happen. We should try hard to fix them, to prevent such things from happening again. But we very much shouldn't excuse them, because they shouldn't be doing that and excusing them partially legitimizes it.
If the Haitians in Springfield were attacked and defended themselves, I would not side with the attackers. I would understand that both a desire to maintain your living conditions (reasonable) and xenophobia (not so reasonable) lead people to react aggressively when large numbers of people come in with a different ethnicity and culture, but if it happened then I expect them still to follow the law, which includes not murdering the people who are there legally.
If the Haitians and old-time Springfielders ended up with running battles and the Haitians occupied much of Springfield and both conducted terror attacks against each other and so on, I would blame both of them to the extent that it went beyond the minimum required to protect themselves (including having adequate defensibility against an armed and aggressive foe). I expect the National Guard would be sent in and everything would be locked down and the agitators imprisoned until people could figure out how to get along despite grievances at least without killing each other.
The time for that has passed, in Palestine.
Palestinians who support Hamas are not innocent. They don't deserve death, but they deserve condemnation. Israelis who support Netanyahu and other right wing figures are not innocent. They also don't deserve death, but also deserve condemnation.
If death comes in addition to condemnation, we can both regret that it happened, and also recognize that the people who died did have the option to push things in a different direction and did not take that option. And that is their fault, even if all the fault is not theirs.