Being more on the business side than the development side, I completely identify with what you're saying. The statement that value is derived from the cost of the alternative is central to market thinkers, of which I identify myself as.
However! This statement struck me as out of place:
> The moralism in these threads is an irrelevant sideshow.
There is not 100% agreement on the moralism of copying digital goods. There is, agree or disagree, a lack of 100% acceptance of copyright as it stands today. This introduces an alternative that costs $0, which messes up the whole market equation. This moral conflict has to be resolved before you can arrive at a market price for digital goods.
We software developers are in a whole heap of a lot of trouble if we expect the broad market to dignify the idea that digital goods are legitimately priced at "what they cost to copy".
I think the moral position of "copy anything" is definitely questionable, but time and time again we've seen the actual markets compete in this way. The decline of music sales is practically a case study in this fact. Whether or not someone will openly state that they evaluate the "cost to copy" option is one thing, but how they act is another. I can't claim that I've never pirated a movie or music, thus I have no moral basis for dismissing that position out of hand.
I'd take the contrary view. If you don't consider "cost to copy" a market competitor, you're in a whole heap of trouble. Position your business in a way that isn't exposed to this type of alternate-pricing, or be prepared to compete with it.
Since appropriating someone else's photo for commercial use without compensation will assuredly get you sued and incur costs far greater than simply licensing the photo, there's an irony to the fact that the discussion on HN about photos is couched in moralism, even though morality is way less relevant to the photo case than it is to the software case (you can easily appropriate software without paying for it, as GPL violators do every day).
There is a difference. GPL software like Linux is hugely valuable, it's value is generally not measured, since it is a cost saving (and a near no-brainer to choose when the quitting is good), not a profit or expense.
Also, MS and Apple (only _really_ since recently) sell software, but Google and Facebook no not.
However! This statement struck me as out of place:
> The moralism in these threads is an irrelevant sideshow.
There is not 100% agreement on the moralism of copying digital goods. There is, agree or disagree, a lack of 100% acceptance of copyright as it stands today. This introduces an alternative that costs $0, which messes up the whole market equation. This moral conflict has to be resolved before you can arrive at a market price for digital goods.