There is a common pattern of Jews advocating for multiculturalism throughout the west, but fiercely protecting the ethnic makeup of Israel. So for many right wingers, it's a frustrating hypocrisy.

For those who do, it would be easily explained by their position in society. If those right-wingers lived in Israel or in an Islamic country, they would be fervent advocates of 'multiculturalism', as it protects their own culture. But being in the majority, it is to your disadvantage to support multiculturalism.

So I oppose multiculturalism, but if I lived in Israel, I would support it.

To put it another way: If you did this in Hungary or Poland, many of the people celebrating this as good for Israel will scream about the oncoming far right genocide. Nationalism for Jews but not for everyone else.

I think Hungary and Poland have even more reason to do this than Israel, as they do not have any Islamic minority - and God help them if they acquire one.

I also think you vastly underestimate that most of those who hate Poland/Hungary also hate Israel.