Are people downloading things that they believe the copyright should have already expired on? (Under the original copyright act it was 14+14. So stuff older than 1991). Or are they downloading the latest Avengers movie?
It's not just hypothetical. In our family we subscribe to 3 or 4 streaming services, but last year we still had to pay $5 to watch It's a Wonderful Life (1946), a movie that was literally in the public domain for 20 years. A Charlie Brown Christmas (1965) wasn't available at any price, except with ads that stretched its 25-minute runtime to nearly an hour. We pirated that one. I don't think most people would think there was anything wrong with that.
You're probably right for everything produced since the second World War, but I doubt people think that e.g. Triumph of the Will is under copyright. I think people have a vague notion of "historical" vs. "contemporary" that starts right around the end of WWII.
My point is there's plenty of good content people want that's 30-70 years old & they don't feel bad about pirating it. My dad by his principles would never download a new movie; nevertheless he's looking up the songs from his childhood on YouTube. He feels entitled to listen to them whenever and however he wants. I think that's a pretty common attitude toward the older stuff.