Books were written before profit long before IP laws existed AND the technology to cheaply copy and reproduce the books was not in existence.
If people really have something to say they will write books anyways. And they will still make profits just fine, just not to the extent they only have to write a couple good books in order to be able to sit on their ass the rest of their lives.
I doubt the reason Ron Paul wrote End the Fed was to make money, actually I know it wasn't because he said the proceeds were going to some charity.
I doubt anyone who is apart of the Mises Institute writes books for profit, since a) they tend to be against IP laws themselves, b) tend to care more about spreading their ideals than making money, and c) give away a lot of books anyways.
I doubt Professors and scholars write books for money, since they make plenty of money already and are more interested in adding to their reputation/legacy/etc.
And just maybe if new books were five dollars instead of twenty dollars people would opt to read more and watch TV less.
But if you really want to give people a legal subsidy just so they can feel a bit more empowered to write a book, then whatever. Perhaps we should apply this to other industries to, just to be fair.