I think the point is that we can't just rely on individual ethics to enact change. People have bills to pay and kids to feed, if it's all on the man at the bottom to say no then a lot of bad software is still going to be created.
There's some (not a lot, but some) power in a profession just claiming to have ethics, even if there is no enforcement and change in the hearts of practitioners.
Plus, at some point, we all just have to own what we do with our lives. It's great to advocate for systemic change but doing your own small part is at least as important.
Do you want to license software developers?
But if you're working on video games, or pizza delivery, or really probably like 90% of software then no.
Failures of a company responsible for this kind of thing that lead to injuries or deaths can result in imprisonment of (at least) the CEO and possibly others. I'm not sure licensing is necessary here, that's what documented process is supposed to manage (change tracking, development process, etc.)