Not too long ago, the average shelf life of a piece of entertainment was about long as a bottle of off-brand cola with the cap missing. Most intellectual properties stopped making money long before the creator's passing, so U.S. copyright laws felt it generous to put the public domain on a 58-year timer, extended to 75 years in 1978. They definitely didn't anticipate, say, an immortal multi-billion-dollar empire to be made on the back of a black-and-white cartoon rodent. But then Disney and Mickey Mouse came along -- in 1928, to be specific.
So when the public domain started creeping up on the iconic first Steamboat Willy cartoon in 1998, the company refused to let just anyone put their dirty, white-glove-less hands on their mascot. Disney and other big entertainment corporations successfully lobbied the government, which passed a 20-year copyright extension called the Sonny Bono (husband of Cher) Act. And because of that, we've been living in a Disney-induced public domain wasteland for so long that newspaper columnists can't even blame Millennials for ruining it.
Luckily, since then the internet has swung along, and according to some activists, Disney and its ilk no longer dare to push for even more extensions, out of fear that they'll get memed to death. But sadly, the damage is already done. Between 1978 and 1998, public domain rights were pushed back decades, meaning if it hadn't been for corporate greed, all art before 1962 would now have been free to use. And who knows what 21st-century culture up to this point would've looked like if basement musicians had had all of Bob Dylan and Elvis Presley to work with? Maybe some postmodern author had made The Great Gatsby & Zombies, and children would've had to reenact with endless middle-school productions of World War II propaganda movies.