I'm looking at this more from a practical level. The morality is important, but when you reduce it to "X exists because of ethnic cleansing" you're leaving out a lot of stuff.

For example, Hezbollah is, according to Iran, part of their "forward defence" doctrine. When they're told to attack a technically superior opponent known to often overreact with force, you know what will happen to those on the receiving end, and you also know that some in Israel will take the opportunity to push their agenda. We can talk about morality, but in the real world these orgs are not there just to protect the people.

Perhaps I'm wrong to focus too much on the practical side of things, but to only care about morality? That doesn't work.

The oversimplification is a problem though. From the early days (WW1, Turkey losing control of the area) to the Zionist movement and the support it received after WW2 because of what happened, to the Soviet Union being their main backer and then their switch to Arab countries and the US backing of Israel, the different wars where Israel was the underdog, to the different peace attempts and the attempts from some on both sides to destroy it, to the current day. Then you have a strong religious aspect, which throws a lot of rationality out of the window. Not to mention the external aspect where you have a handful of countries supporting their side and often not in the best interest of the local people.

But maybe you're right and this all very simple. Maybe many generations were too dumb to see it. I personally wouldn't mind if you came up with a plan to fix it! Good luck :-)