If there is no such thing as an atheist Christian, how can there be an atheist Jew?
An atheist Jew is someone whose ancestors, perhaps many years ago, practiced Judaism but who has somehow managed to cling to this identity.
This person does not believe in the Jewish God, he does not follow the Jewish law, he does not read the Bible, he does not celebrate, or often even know the meaning of, Jewish holidays, he is only very vaguely aware of the history of the Jews, he does not pray, he does not visit the synagogue.
What makes him a Jew? If he thinks of his alleged Jewishness, what separates him from all others? Nothing, I submit. “I am defined by what the Nazis hated” is not an identity.
If Jews are merely a “people,” then not for long. If you are an “atheist Jew,” hopefully your children will convert to Christianity.