"bits" is a very disingenuous way to look at creative work. The end product is "just" 1s and 0s in the same sense a Porsche is "just" atoms.
I understand a little under a decade of copyright protection when you had to horse and buggy your manuscript to a printer and they shipped it by train and boat around the nation to salesmen who again went by train or carriage to sell it... But in the world of one-click publishing? A hundred years plus? Really?
The window of protection is now less a window, and more a gaping wound in the side of creativity, as seen here.
As far as the length of copyright (which, I agree, is currently too long), you can thank Disney for that.