In a more moderate situation land and property are organized and enforced by the state, because this protection is more efficient for everyone.
Intellectual property is incredibly hard to enforce, because anyone can copy an idea, or bits on a hard drive, so you'll have to come up with convoluted solutions to check for the presence of information at every point in a network, and we're expecting citizen to pay taxes to pay the police force who will enforce those rights in favour of the owners.
There are other, more efficient means, but they involve the richest to get a smaller cut (e.g. instead of the state enforcing DRMs for free, they have to pay for good DRM themselves), so it's very valuable for them to leverage the state to enforce their self-proclaimed rights.
But there is no conceivable way to enforce things like copyright or patents without something at least as powerful as a government, since they are supposed to be binding on every single person, everywhere, all the time.
IMO the concept of "intellectual property" is at best orthogonal to that of a "free market".