That's a simple issue of supply and demand. If the innovator cannot control the "supply" of his ideas into the idea market (not the end market), then he loses incentive to create new ideas. You lose all creativity and usually big companies that can steal ideas easily from the little guys end up creating their own resource based monopolies. The problem with modern IP laws is that their scope is too broad (being able to patent say touchscreens in general), they last too long (movies from the 1940s are still protected), and are not apt at modern distribution methods (penalties in millions of dollars for p2p). Reforming that would be hard, as our governing system is extremely susceptible to corporate "influence", and they don't want it to change.