Open Innovation obviously is inspired by the Open Software movement.
Open Software works because it benefits from some specific features. Therefore though, it is hard to copy blindly to other fields, like innovation of tangible products.
First, in Open Software there is mutual gain, almost without loss. Sharing your software creations implies anyone can use it; in return you can use everyone else's shared software.
Second, in Open Software cost of sharing is neglectible as reproduction and distribution costs are virtually free.
Sharing other types of intellectual property, like music or text, does fulfill the second condition but does not fulfill the first.
There's no direct mutual gain. Musicians, theatre artists or fashion models do not receive anything in return from sharing on the internet. Apart perhaps from a reputation or even fame that they can exploit otherwise. After all their creations show their capabilities that they can perform later on. Otherwise all but the satisfaction of bare attention is gained.
Photographers, painters or text writers apparently loose their creations alltogether by sharing them with the world community. Their creations require an investment in effort, which may become sunk costs if they're just given away. The same goes for inventors.
They also need exposure but in a protective environment.