Hmm, you know, the RIAA uses that same logic, but there were a couple of studies that showed the opposite: people who downloaded music spent more money on music (either discs, concerts or other products) than people who didn't download music. I wonder if the same holds for movies? I kind of suspect it does. If indeed it does, not only would the studios be attacking their customers, but attacking their best customers. If I were them, I would have wanted to test that one before launching the lawsuits.
Perhaps what worries them is that those who are spending more may be doing so because they aren't having to pay members of the RIAA. I have a subscription to Magnatune and often buy music from services like Bandcamp. I may well spend more on music than the majority of those earning more than me, but I tend to be very concious of where that money goes.
Amanda Palmer was originally on a major label and I certainly listen to the album recorded under them; however, lacking any incentive on merchandise, or access to live performances I had no accessible way to support her directly. Eventually she started releasing projects distributed on Bandcamp and I was able to overspend on those albums in the knowledge that the money was not going through an abusive label.
The issue here is the lack of distinction between the music industry and the recording industry, I may be a great customer for the former but am a pretty lousy customer for the major players of the latter.