The answer, according to Dara Horn, is not simply that American Jews don’t care. She writes:
The reason American Jews don’t learn Hebrew is because they think they can’t. And I understand why. For much of my life, Hebrew scared me. This became rather inconvenient while I was pursuing graduate studies in Hebrew literature. But I had reasons to be scared. . . .
You see, I already knew that I could never actually learn Hebrew—real Hebrew, fluent Hebrew, Hebrew where you could understand Israeli TV—simply because only three kinds of American Jews were allowed to learn Hebrew, and I wasn’t any of them.
First, I wasn’t Orthodox. No one was sending me to a gap-year yeshiva; no one I knew threw around Hebrew phrases; no one I knew went on aliyah. Second, I never lived in Israel and had no relatives there. . . . And third, I never went to a Jewish school. . . .
It is now very unclear to me why more American Jews do not learn Hebrew. The excuses about assimilation and so forth do not explain why already-committed Jews do not learn Hebrew better, or why we are letting supposed impossibilities stand in our way. And now is exactly the moment when a massive initiative encouraging Diaspora Jews to learn Hebrew might actually work. With Israel’s high-tech energy, and with the Israeli government’s eagerness to draw in Diaspora Jews, shouldn’t there be an app for that?
Read more on Stroum Center for Jewish Studies: https://jewishstudies.washington.edu/hebrew-humanities/dara-horn-my-first-hebrew-test/