You're inappropriately focusing on revenue and not access. Suppose I had a goose that laid golden eggs /ad infinitum/. I have infinite net worth, but if you take one of my eggs, you now have access to value which you otherwise wouldn't have had. Just because your theft didn't impact my revenue it doesn't follow that you didn't steal.
IP is actually quite similar. Suppose I wrote a book (.pdf) that contains important business information about the future of the oil market. I obtained this information at great personal cost. Your accessing that information doesn't remove that information from me, but it's still stealing access to information you otherwise wouldn't have had.
Saying, "But I wasn't going to buy your crappy business book anyway!" doesn't change the fact that you've still taken information that doesn't belong to you.
IP is actually quite similar. Suppose I wrote a book (.pdf) that contains important business information about the future of the oil market. I obtained this information at great personal cost. Your accessing that information doesn't remove that information from me, but it's still stealing access to information you otherwise wouldn't have had.
Saying, "But I wasn't going to buy your crappy business book anyway!" doesn't change the fact that you've still taken information that doesn't belong to you.