It's that mixed with "movies are real" syndrome. There were so many movies in the 80s and 90s about deforestation. Every other bad guy in children's movies was some rich, obese lumber baron who smoked cigars and didn't care about those blasted forest creatures as long as I get my money, confound it! Insert scene where the baron uses a puppy's head as an ash tray for extra subtlety.
Any 70s-90s kid living in the city with sufficiently negligent parents grew up to believe that America's forests are being clear cut out of pure spite for the spotted owl. After all, Hollywood won't shut the fuck up about it, so it must be a big problem, right?
It wasn't until someone sat down and put together the facts that people stopped thinking the ever-present "desolate, grassless field covered in stumps" scene was real. As soon as the fact that America's forests are growing became quick and easy to demonstrate, the Save The Trees movement died. Well, it didn't die. It was replaced with Muh Old Growth, which is 1/100th the size and nobody really cares because it's harder to draw a scary picture about it. Also because there's very little hard science behind old growth forests actually being any better than any other kind of forest.