I am not surprised. It seems only some of the Conservative, the Orthodox, and Hasidim identify their affiliation as a religion. Judaism has become an ethnicity.
The New York Times covered its Holocaust coverage and revealed some interesting truths about American Jewry during WWII. The report found that the NYT reporters dutifully reported the actual conditions in the camps. Their existence was well-known to regular Times readers. The publisher, an American Jew, dictated that no front page coverage take place. The paper was American focused then. He believed that American Jews' first loyalty was to America and that Eastern Europe did not matter. Since there was no jolting and dramatic front page expose, no political pressure built.
I'm not certain whether I identify myself as Christian in religious terms to the exclusion of any other religion. Perhaps many main stream Protestants are the same. I respect the culture in which I was born. Were I born in another culture, I doubt I would be Christian. It becomes extremely difficult to answer these questions with candor. Life is more nuanced.
Strong Jewish identity does seem to exist which makes sense. I believe there were revealing numbers relating to interfaith marriages, too.