I don't really understand their position. Surely the option that leads to least Palestinian deaths would be something they want? It's honestly just weird.
Some of you Palestinians may die, but it's a sacrifice Hamas is willing to make
This is very true, taking a contrarian stance is an easy way to “show” (pretend) that you have an edgy personality. This I think covers most of the young white Westerners.
The other part is just antisemitic people, of which a lot exists even in Western countries (and not just immigrants, who are often blamed solely).