That doesn't seem too awful. It basically means everything from the 80's or early 90's goes into the public domain. After that much time, it's a crime keeping

That doesn't seem too awful. It basically means everything from the 80's or early 90's goes into the public domain. After that much time, it's a crime keeping the copyright monopoly: it's either exhausted all possible profit, so there's no point, or it's been around long enough that everything after it is influenced by it, like season 4 and earlier of The Simpsons, and the original Star Wars movies. In other words, that seems like a decent cut-off point to say that if you still want to hold copyright on them, then you're rent-seeking off of stuff that has kinda become "cultural identity" stuff, specifically because it's what people grew up watching and influenced by.