Well, Muslims claim that Jesus is one of the main five prophets of Islam. When they say that, I don't accuse them "of appropriating Christian culture".
Au contraire, it's a honor for a Christian, and I am really happy to hear it.
There is no Christian culture. Christianity is a religion. It is your prerogative, as a Christian, not to take offense at another religion appropriating Christian tradition; but that doesn't mean that that's not what's going on, or that another Christian isn't within their rights to take offense at it.
The great issue is that Jews have always mixed up culture (or nationality) with religion. They are two different things.
Christians don't have this problem. A Christian can be from any part of the world. They can be Spanish, Japanese, Africans etc etc
Muslims don't have this problem either.
Christianity and Islam are religions. They are not tied to a specific culture. Judaism, properly speaking, is a socioreligious ethnicity: it is an identity that combines elements of culture, religion, and nationality, all inextricably linked with one another. In this respect, it is less like Christianity or Islam, and more like the religious/cultural way of an indigenous tribe, like those of Native Americans or Africans or Pacific islanders: the religion is specifically tied to the culture, the language, the history-- it's all bound up with one another.
It is not that Jews are "mixing up culture/nationality with religion." It is that you don't seem to understand that sometimes all those things can be deeply interconnected in a single identity.
Judaism is
different than Christianity. Not just in terms of theology, it is a completely different phenomenon. To presume it is just Christian religion without Christ is both absurdly reductive and utterly erroneous.