> Without any IP laws, you could, in a thought-experiment
> world, spend millions of dollars to create a movie,
> release it, and not make one dime back on it. That would
> be the last such movie produced. That's "underproduction".
This is technically true, but IP laws don't provide any guarantee to the contrary. They are irrelevant to that thought experiment. Copyright does not guarantee profit.
There's a decent argument to be made that this would happen more often without IP laws, but then you're moving away from the thought-experiment world. Doing that makes it not clear-cut.
All of this is anything but clear-cut. However, I think that in a no-IP world, producing 'commercial' movies as we now know them would be far trickier.
Of course copyright does not 'guarantee' profit: you can make a shitty movie and lose money. However it provides some protection for content producers and indicates a fairly clear path to making money: make something and sell it.
There's a decent argument to be made that this would happen more often without IP laws, but then you're moving away from the thought-experiment world. Doing that makes it not clear-cut.