Big tech companies are biased to sourcing from big name universities that have a lot of foreign students, and big tech companies were much more likely to go through the effort of H1B than smaller companies. As such your candidate pool is more heavily skewed than elsewhere.
There wasn't any demonization of math when I was in school, but no shortage of "you can grow up to be anything" and "do what you love" rather than "get a job that will pay for doing all the things you love".
There's nothing wrong with being a librarian or getting an MA in Museum Studies, aside from the price of getting the degree and the low odds of getting a job without waiting for someone to die so another position opens up.
There's a reason you won't find a lot of foreign students pursuing them, though.
The conspiracy here is that somehow US spending on primary/secondary education ranks among the top, yet we are unable to produce competitive college students. And we mask this very serious problem from directly rippling into our economy by... importing students and workers.
All the conspiracies theories can be put to bed by walking into any engineering department (maybe outside of biomedical engineering…which makes me think this may be related to how Americans demonize math) and observing that the majority of students are foreign or maybe second generation immigrants.
This ratio gets worse because American students are disproportionately more likely to follow up their engineering undergrad with law or business school, so even if they may be engineers they’ll get into business and/or something like patent attorney going forward.