Patents and Human Nature
Until relatively recently, most Humans organized themselves into tribes of between 50 and 200 individuals. Innovations within the tribe would arise from just one or two individuals, with the rest of the population copying (learning) from the innovator. Humans are nothing, if not champion imitators. These innovations would also be traded for other necessities when tribes met at festivals and other gene-mixing events. They would not be given away for free, but they were sometimes stolen (along with their women) during conflicts.
Historically, innovations that originated within the tribe were freely shared with its members, resulting in increased well-being for all the tribe, including the inventor. Today, because of the ease of communication, we are approaching a type of singularity in our tribal organization that is allowing us to act more like one big tribe. This changes things. Sharing, with what amounts to an extended family, and sharing with a large population which may even be on the other side of the world, have very different outcomes. In the latter case, benefits arising from an innovation could be enjoyed by the imitators and capitalized on by commercial interests, yet not shared with the actual inventor.
This type of situation, fails to provide incentives for innovators, which leads to reduced effort and reduced sharing by innovators. Communism may have seemed like a good idea, but that hypothesis failed to take individualism into account, resulting in its complete failure during the last century. Capitalism, on the other hand, is the corollary of communism when it comes to individualism and ownership of property. (As an aside, if capitalism does not temper itself with some socialism, it will fail just as spectacularly once the disparity in society becomes unbearable.) The right of ownership is a powerful incentive, and those rights need to be protected. That is what good patent legislation does.
Disclosure: I am/we are long WILN.