But even if I did - why is this the root problem here, and yet not a problem for the millions of other people displaced in the world around the same time, and since then? There have been tens of millions of refugees around the world since 1948, they've all resettled elsewhere and stopped being refugees, not kept the idea of endless resistance until they reclaim their land, despite there being no way to achieve this without causing just as big a humanitarian disaster now, if not bigger.
You're right that if you consider the central issue to be the existence of Israel, everything else is "propaganda". But in no other case is it considered legitimate to wage endless war built on the idea of completely destroying a country that is recognized by almost every other country in the world.
So a more correct thing to say is that the central issue is that the Palestinians have never agreed to any form of living side-by-side with Israel, despite having several opportunities to do so, and have demands that are quite simply illegitimate.