You're right, active evilness is not the only case or necessarily the bigger problem. Not knowing what you're doing doesn't mean you aren't acting unethically though when you risk others' welfare for your own gain.

But actions your automated systems are still your actions, regardless of intentions and outcomes. If we hold people responsible for negligently causing damage, we should also hold them responsible for negligently causing damage using an automated system. And of course, we should positive outcomes a system causes to the people behind it as well.