That strikes me as one of those perfectly logical justifications for contributing to a problem: "Well, if we didn't produce cigarettes, someone else would anyway." It's also a red herring; it doesn't matter if someone else would or not, all that matters is whether or not we did the deed.
Well, you are right here, but that's essentially the point I try to address. Everyone of us has to decide on his own if he wants to work on something, which has no positive effect on overall society.
