The tautological answer is that it's because we the people have made laws that in certain specific situations make people criminally responsible for how the product of their labor is being used.
The practical answer is that it's because we do want to discourage criminals from "splitting liability" by having most of a gang doing some illegal goal together stay "clean" and only delegating a single "fall guy" for the final touch; so criminal law is explicitly written to consider everyone who knowingly assists a crime to be partly liable as well.
Engineer doesn't imply honesty. In those jurisdiction where it's a protected title, it just implies that you have some mix of STEM topics in your degree. Software engineers, in these jurisdictions, have that mix, and are as real as bioengineers (a.k.a hospital lab workers), chemical process engineers, construction engineers, etc.
No one has had their engineer title taken away for being a crook, as far as I know. Unless the crooked thing they did was fake their diploma.
It doesn't imply honesty. It does imply liability, so if something bad happens because you're dishonest, you will lose the title, and suffer other consequences.
> No one has had their engineer title taken away for being a crook, as far as I know
This seems an absurd claim, unless you're going to get very pedantic about some distinction between "engineer title" and "legal right to function as an engineer".
This is one example found after just a few seconds of searching, but it is absolutely commonplace to have your engineering license revoked for carrying out criminal activity.
> In those jurisdiction where it's a protected title, it just implies that you have some mix of STEM topics in your degree.
This seems a bizarre claim too. In jurisdictions where membership of a professional licensing body is necessary in order to refer to oneself as an engineer and practice as an engineer, it is absolutely not the case that all you need is the right "mix of STEM topics in your degree". It means you have a certain degree, have completed a set amount of work experience, have completed a professional certification exam and then maintain that license, which may require meeting other requirements periodically. And yes, "not being a crook" is certainly one of those requirements, and being involved in major criminal activity, especially criminal activity related to your professional practice, is absolutely grounds for having your license and certification as an engineer revoked.
Why not? Why do we keep Apple responsible for Foxconn's labor practices? Isn't Foxconn an independent company after all? The reason is because we don't want evil to spread by externalizing the responsibility to third parties.
Most things are ambiguous, so you can have an argument about what intent was. Even things like firearms, you can say, "well, I made this gun so people can use it in self defense".
This seems pretty unambiguous though. Sometimes you're just facilitating breaking the law, or making things dangerously unsafe.
