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.