Whoa, that's a bit of a jump there. I agree that the open letter is a giant rationalization and a fundamental misunderstanding of the market-- particularly the whole, "I'll buy your future work," as an attempted justification, but to even begin to compare piracy of digital content to shoplifting is disingenuous at best, which is to say nothing of your attempt to make him sound like he supports misogyny.
If you own a store and I shoplift from you, I'm stealing a product that you paid for, essentially transferring your capital to me. On top of that, you can no longer sell the product to anybody else, depriving you of future revenue, thus making it impossible to ever recoup your capital expenditure.
If I "steal" digital content from you, your position does not change at all, except in the hypothetical, in that you can argue (though no way 100% prove) I am less likely to purchase the product in the future. You still have every chance of recovering your capital expenditures, because you have not lost any real assets in this process. If I turn around and share the file, it could be argued that there is a network effect, but again you still have to prove a causal link between not downloading and purchasing.
If you think about it, the "piracy" model is no different than the radio or television model from a user's perspective, except that they're in control of the content/programming schedule. Why should people think it's bad to download television shows when they're used to seeing them for free on television their entire lives... likewise for songs on the radio? Do you really think that people were less likely to purchase a record because it was played several times a day on the radio?
In a way, content distributors at this point have no business model except for providing artificial scarcity.