If you are a trader and get attacked by a pirate, then its non-consensual regardless of whether the pirate is a player of an npc.
Moreover, if you are a trader I think you would never want to be attacked by a pirate.
I disagree with both of these points.
I want the experience of taking the dangerous trade route off the coast of Somalia for higher profit. I'll be flying either a well equipped "armed merchantman" like a well tooled up Cobra mk 3, or hiring a couple of escorts if I'm flying the classic fat mechantman. I want to make it through the trade run, but it doesn't mean I don't welcome the danger and the challenge.
I think you're simplifying this a little too much. I doubt the "traders" as a general group want to just fly between trade hubs with nothing ever happening. They just don't want the whole thing to turn into a frustrating and demotivating series of getting robbed time and again. Danger and opportunity in the right mix is the key.