There is simply no way to sell on the free market objects with an almost infinite supply without appealing to outside forces like state regulators.
How would you feel about companies using GPL licensed code in close source products?
In what context? A laissez-faire economy without patents and copyright? You'd have to also eliminate law enforcement when it comes to licenses to render GPL useless, but I don't see how is this relevant to the discussion about the intrinsic economical value of digital data that can be copied at an almost zero cost.
The point I'm trying to make is, that the protection offered by copyright extends beyond monetytization as it's often reduced to. (understandable in a capitalist econonmy, where Almosen everything has a price) Instead it allows the right holder to limit how it's distributed or attach conditions to the distribution. The GPL with its limitations on how I may use a piece of software licensed under it is one outgrowth of that. If you reject copyright, especially for digital goods, you should be fine with the GPL becoming useless.
You have a point. Yes, the loss of enforceable licenses would be acceptable in a system without artificial means to stop the flow of data. It's not like most of us have the means to go to court over GPL infringements anyway.
Good, because this has actual value, unlike copies of digital data.