That's a comparion of tangbile with intangible theft. Yes, they're both theft, but you can count it the same way.
Piracy is rampant, because it's too easy. In my teenage years I filled up with music I would never have listened to, some I never got around to listening to it. I just grabbed it cause it was there during my time wasting expeditions. Alot of people that pirate photoshop don't do it out of necessity or intend to use it for it's purpose. They just have it because they can.
Does that mean that record label lost out on the sales of music I grabbed, or that adobe lost on sales from joe blow who has photoshop on their computer for no reason other than to have it on there?
Piracy has huge numbers of distributed copies I agree wholeheartedly, but actual "lost sales" is smaller number, depending on the data in question.