Interesting! A hypothetical question...
If you were to find out that software you wrote for a UAV was responsible for murdering an innocent civilian, would you still "feel 0 guilt"?
If you were to find out that software you wrote for a UAV was responsible for murdering an innocent civilian, would you still "feel 0 guilt"?
In my opinion, unless you're making active efforts to live without benefiting from someone else's harm (following a Jain diet, living in the woods, living off the land, etc), you're no different than me if I programmed a drone that person B constructed for person C to deliver to person D who ordered its use by person E who deployed it. It's just easier to convince yourself you're not responsible when everyone else is also doing it, and when believing that you're not harming others affords you the convenience of chocolate and computers.