I agree with the sentiment, but considering the catalog that Disney has amassed it's fairly hard to stay away from their properties if you want to partake of much media-based culture.
When a reader thinks of the "catalog that Disney has amassed" that is part of our "media-based culture", they are overwhelmingly thinking of titles that would remain copyrighted --- for quite some time --- even without the Copyright Extension Act.
Does even Disney really push Mickey Mouse cartoons much any more? They seem to mostly focus on other product lines. I wonder just how much they would lose out on with no further copyright extension.
I don't know, but to the extent you're not talking about Mickey and Donald, you're not really talking about copyright extension anymore; under any reasonable copyright term, they'd still own Frozen and Toy Story.