Is Jewish an adjective like Spanish?
If you describe someone as 'Spanish',' Danish' 'Polish' you imply a historical link to a land, a piece of real estate. This does not apply to Jews. Describing Jews always presented a problem. I am described on my birth certificate as Israelite, though there was no Israel in existence till many years later. The term 'Zsido' Jew, just as the term 'Yid' had many negative connotations, exclusiveness, poverty, lack of genteel good manners. As an acculturated, assimilated Hungarian, 'Israelite' was a description akin to Catholic (in fact, Roman Catholic to distinguish it from other forms of Catholicism) Protestant (with its different variants, Reformatus, i.e. Presbyterian, Lutheran, Sabbatarian). It implied that I was part of a happy family of different ethnicities. The price my grandparents, or more like great grandparents had to pay for it this was that they had to give up their language, in the case of my grandparents, German, their Jewish culture, and their religion was viewed through Christian eyes and norms. The notion that we were all part of a happy, civilized, liberal family whatever our religion and ethnicity was blown out of the water by the deeply ingrained anti-Semitism of European Christian society and ultimately the Holocaust. We have to face that we are Jews, with all that the term implied.
The Zionists also faced these issues. They were not happy to transfer their European Jewish culture and traditions to a new land. They deliberately abandoned Yiddish, the language of Eastern European Jews, they abandoned the religious practices, they abandoned, or tried to abandon the high culture of Western European Jews, Herzl wanted the language of Israel to be German, Weizmann had difficulty persuading the Zionist leadership to set up a world class university in Jerusalem, they wanted peasants with socialist leanings, Hubermann faced great obstacles getting visas for Jewish musicians to set up a symphony orchestra. The last thing the Zionist vision needed is more Jewish fiddlers. The term Israeli doesn't conjure up an image of a Talmudic scholar, a shop keeper, a cobbler, a wine merchant (as were members of my family) a violinist, a professor, or for that matter a ganev, a thief, a crooked operator, yet the term 'Jew' has all these associations. A Jew is, to a greater or lesser extent, and outsider, with no attachment to the land, and the less he is an outsider the less he is a Jew. His value to society at large is exactly this outsider's perspective.