[logfromblammo]

You are forgetting that private entities are also members of the public. Just because one private entity may benefit does not mean others cannot. When the commercial vehicle uses the public road, it does not exclude anyone else from using it, except to the extent that it causes traffic congestion. When the public buys a bus, it has the bus. The company it buys from could have sold that bus to anyone else who wanted one.

In this case, the private patent-holders take the benefit and exclude the rest of the public from it.

If you need it to be more clear, public funds should not be used in a manner that exclusively benefits only a few enumerable private parties. It doesn't quite roll off the tongue as easily, but there it is.