Does it count as being in the market if no exchange of money takes place? Is Github a market, for example? If not, this would seem to invalidate the idea at least when the material is found by chance or provided free.
>There are people who, knowing you are like them and enjoy that sort of thing, will make it for you.
That's true, but if you're using this as an argument against all the material then I think I should step in and say that it does not apply to all the material, or at least, you haven't provided evidence that it does. I don't doubt it happens, but to use this as a general argument seems to fall flat on its face.
The "good porn" analogues are people who record themselves because they like the attention. But I think this is a minority.