Yeah, it protects Jimmy from having to unconditionally contribute to society & its many organizations.

It allows Jimmy to set conditions and control who can use it and who cannot. For example, he can ally with one particular big corpo (or even start building one himself) so they can hold that thing hostage and require agreements/fees for the use of that thing for a long long time.

So now, instead of all people, including big (and small) corpos, having free access to the idea, only the friends of Jimmy will.

The reality is that if it wasn't for Jimmy, it's likely that Tommy would have invented it himself anyway at some point (and even improved on it!). But now Tommy can't work on the thing, cos Jimmy doesn't wanna be his friend.

So not only does it protect Jimmy from having to contribute to society without conditions, it also protects society from improving over what Jimmy decided to allow (some) people access to. No competition against Jimmy allowed! :D

Even without patents, if the invention is useful I doubt the inventor will have problems making money. It would be one hell of a thing to have in their portfolio / CV. Many corpos are likely to want Jimmy in their workforce. Of course, he might not become filthy rich.. but did Jimmy really deserve to be that much more richer than Tommy?