There's a few points of critique.
Religion is not the same as nationality, there isn't a country that is dedicated to Christianity for example. (well, you have the Vatican but you get what I mean, it's not a nation) It's a different thing, so you can't argue that Jews have no home since they too have a nationality from the country they were born in, like everyone does regardless of religion. I'm not arguing against Isreal existing to be clear, just that having a country for a religion isn't some given right that only Jews don't have. They mgiht be the only ones to have it depending on how interpret it.
There's interpretations of zionism. At its core it's the belief that the religion should also be a nation. But different sides form around the "how" part. While having a country to live in isn't bad itself, if zionism means driving out others or straight up genocide of others, then it's fair to bluntly oppose it.
Isreal exists now, but the continued killing and takeover of Palestine is horrible. And these days many bind zionism to the acts and opinions that flourish in Isreal that portray Palestinians as some evil that should be removed. It think opposing an nationalistic view like Zionism is a reasonable action when the country is engaging in invasion.
That's a good clarification, but I do not feel it changes much. A non-Isreal nationality now is still a thing they possess. No one chooses where they are born either way. Their ethnic identity is still there, but I do not think it gives them ground for land after they were dispersed originally. But regardless of that, they got Israel. It's there now, and removing it also not an option.
It's rather ironic, Jews are now killing off another ethnicity from the very same lands they themselves were driven out of. Sounds like a revenge story, but it's just a cruel inversion of the same antisemitism that Jews have suffered at least twice now with their initial dispersion and during the second World War.