"Content" has the stink of failure (and it's a lie, besides)

Intellectual property is generally about economic prerogatives. In principle, to create an incentive to desirable ends such as profit or progress, and in practice a monopoly on economically-salient rights. This encourages people to think of creative works in economic terms – hence, “content”. “Product” is an earlier term referring to artwork that means much the same thing in this sort of context, but which seems to have gone out of style.