But opponents of Israel didn't always make that argument. They used to make the opposite one!
From Brooklyn-based Arab Christian newspaper "Caravan" in 1956:
Here, the Arab argument was that everyone knows the Jews are indigenous, just like American Indians - and the idea that they should be able to return to their land is as absurd as allowing native Americans to take over the areas they were ethnically cleansed from.
If the exact opposite argument is used for the same purpose, it is obvious that the arguments are props. Hate for Jews is what animates these people to make their arguments, but even they don't believe them.