Basically, the argument is that you should not have ever charged for your art, since its viewing and utility is increased when more people see it.
The lack of empathy comes from our love of open source. That's why. These engineers have been pirating books, movies, games for a long time. Artists crying for copyright has the same sound as the MPAA sueing grandma 20 years ago.
Now was Aaron Schwartz (what I view as on ultimate example of this open source idea you cite) naive, no. Maybe he knew in his heart the greater good would outweigh anything.
But I don't think we should judge too harshly merely falling on one side of this issue or not. Perhaps it's down to a debate about what creation/truth/knowledge actually are. Maybe some creators (of which aritsts and computer scientists are) view creations as something they bring into the world, not reveal about the world.