A physical good (food, clothes) is depletable, and in that way too unlike digital data, which is for all practical purposes undepletable. But if you consider even highly inexpensive physical goods, they have various substantial costs of transportation, inventory, etc. associated to them, and thus they are not truly as fluidly and effortlessly reproducible in the way that digital data is reproducible for zero cost.
You have a network in which it is so convenient to share that it's almost begging you to. There's a lot of fundamental rethinking of commerce here, and I was quite bugged by it all when I started looking into it myself. But when you see how badly the bigger half of people in this world are suffering it's easier to see why this is necessary.
You're going to get a much better explanation of things from Moglen himself than me -- here, the transcript to the video I linked (if you're unable to watch the video): http://en.wikisource.org/wiki/Free_and_Open_Software:_Paradi...
Right, that's why I said "not for free but for their low marginal cost." You're hand-waving with the "zero marginal cost" argument without addressing my counter-point. If the fact that something has a marginal cost approaching $0 means you are morally obligated to provide it for a price approaching $0, why is there not a similar moral obligation to provide something that has a marginal cost of $3 for $3?
> If the fact that something has a marginal cost approaching $0 means you are morally obligated to provide it for a price approaching $0, why is there not a similar moral obligation to provide something that has a marginal cost of $3 for $3?
If it were up to me, it would be -- or roughly something like that. But I have supposedly radical views on a lot of things (FWIW I affiliate to a local socialist party). I think a lot of the decisions made by big pharmaceutical companies, retail corporations, etc. are morally reprehensible. To give you a more direct answer of why I do not go down the streets at night shouting for change on this: because it'll be much harder for me to achieve that change. It'll be much harder for me to be an influencing force of bringing about a system I would be happy with. But because I am someone of a technical background, this fight is the fight I choose to participate in. Also, charging something $3 for something that has a marginal cost of $3 sounds kind of lousy -- I'm sure there's got to be a more elegant way of doing that. :)
The analogy can be made between scientific funding body and investor, where an investor expects a return on their investment. In this version of reality, the funding body would encourage distribution of the product at supra-marginal cost, with some percentage of that cost funneled back to the funder. This situation is rare in science, i.e. a journal company paying the NSF royalties on subscriptions whose content was paid for by the NSF.
E.g. say the government gives me a $1 million grant to pay the costs of developing some military technology. As part of the bargain, I get to keep any commercialization rights. Should the resulting technology be free to the public? No. Nobody sane works simply to cover their costs. The commercialization rights are my profit in the arrangement. If I had known that they would be rendered useless by the government giving away the resulting technology, I wouldn't have settled for a grant that simply covered my costs--I would have bargained for costs + profit.