The patent system has been established to aid spreading of technologic progress in the first place. As porter pointed out, the patent system is perverted to something protecting commercial interests, thus being an encumbrance to anyone who needs to make use of new technology. If there was an option for anyone to use the patent system for free, I might agree to a protection of commercial use of intellectual property up to a certain degree. But many individual persons can not afford patent fees, while some huge companies churn patents out as soon somebody got an idea about an idea. So one might dismiss the whole patent system without doing something bad, as mankind could freely use any improvement all over the world.
But I agree that there should be some protection for actually designed and manufactured products. A given piece of software may be protected from piracy, of course. As it comes to obsolete software products, there might be place for a law allowing to expire license restrictions when the product is not supported any more.