When old (and stupid) patents hinder innovation (what happens all day today), than the patent system becomes the biggest hindrance to innovation. Somebody said about IP: When it is better to "own" old IP than to make new one, the system is strangling innovation, nothing else. We already at this point (and it was fostered by the owning people).
Patents once where made up, to bring inventors an incentive to share their inventions with the others. But this "sharing" brings only benefits to the society, when the inventions bring any knowledge gain to the community.
Software patents are the worst: Most of them include trivial things that do not bring any new knowledge to the industry, but are blocking other inventors. Good example is Amazons One-click patent (but this is only one of maybe thousands examples): What is the knowledge gain of the world, by having this patent?
This system is for the "owners" not for the "creators"!