[ptmx]

Sure, easy piracy is a part of reality and businesses should, as a pragmatic matter, adjust their business models -- that's neither here nor there.

When I talk about being able to honestly assess willingness to pay, I'm talking about the pirate who claims that they wouldn't buy a good anyway so they might as well pirate it. It might be true, but all we can really say from the outside is that they value the good at least $0 worth, so their willingness to pay is somewhere between 0 and infinity. You can't put an upper bound on their willingness to pay just because they didn't buy the good when they got the good for free.

I don't particularly care if people pirate, but I find that pirates tend to do a fair bit of mental gymnastics trying to justify why piracy is ethical; I think the "I wouldn't pay for it anyway" argument falls under that umbrella.