Partial title can be transferred for property, and in real estate that is considered "ownership". But it isn't really ownership unless you have the full and exclusive use of the property. Deed restrictions obviously preclude full use. What you own under a restricted deed is the right to certain uses of the property; the seller of the deed retains ownership of the other uses listed as encumberments. Neither party really owns the property as a unit; they respectively own the rights to different uses of it. If the deed holder sells the deed to someone else, the encumberments still remain on the property, as rights retained by the issuer of the deed. If the second party in this scenario attempts to sell an unencumbered property, he is defrauding the third party, who is in fact purchasing a restricted deed, with the original owner having the right to enforce the restrictions, he being the factual owner of the title to the uses of the property which they describe.
The difference between that and IP, as I mentioned above, are the facts of physical property and explicit agreement. The holder of a restricted deed can no more justly transfer an unencumbered property to a third party, than he could justly sell a stolen watch to a third party. But in the IP scenario, if Al shows Bob his idea under the contractual term that Bob may not show it to Charles, and then Charles nevertheless comes into possession of the idea, Al cannot take the idea away from Charles. Because it is now in Charles's mind, and hence, it is Charles's idea. Nothing has been stolen from Al by the fact of Charles having come into possession of the idea, nor are Al's rights violated if Charles uses his property to express the idea. Al's only claim is against Bob, with whom he had an explicit contract, because no property of Al's was transferred, justly or unjustly, to Charles.