"Protection of private property exists to the extent it's judged useful to society. Protection of so-called intellectual property exists to the same extent."

Protection of private property is to prevent theft. We both can't have your car. If I copy your software, we both have it.

Protection of intellectual "property" was granted as incentive to create. It was (is?) a time based monopoly on your creation. At some point the protection ended. This was a benefit to society as it allowed ideas to be built upon.