In order to do that, you have to have a central authority that actually keeps track of copyrighted works, who owns the rights to it, if they've been extended, if the fees have been paid, etc. On top of that, you need to think about the broke independent author who can't afford to extend the copyright on that 5th year because they got a divorce, got in a car accident, and landed in the hospital. Or the high schooler who wrote a book for NANOWRIMO, self-publishes it, but doesn't know the first thing about copyright law or needing to continually do extensions. The copyright inevitably lapses, and some publisher finds it, likes it, and starts printing copies and selling them because it's in the public domain.
I really, honestly believe that we need to reform copyright, but I also think we need make sure that it doesn't favour people with money and people with access to intimate knowledge of copyright law. I think everyone probably has at least one copyrighted work to their name, so we should make it a goal that just about everyone should be able to understand copyright.