Those percentage of SWE working on critical infrastructure should be licensed and legally liable, yes. You shouldn't need a license to build a CRUD app, just like nobody needs a license to build a treehouse in their backyard. You should need a license to work on a car's braking system (https://safetyresearch.net/toyota-unintended-acceleration-an...) or radiation therapy machines (https://en.wikipedia.org/wiki/Therac-25), just like you need a license to engineer a highway bridge.
People do things based on motivation. People motivated by pride and passion know that their work reflects upon them, so they have an incentive to care about quality. People motivated by money know that their paychecks will keep arriving as long as they keep meeting a minimum bar, so they're not incentivized to care about quality, but they are incentivized to care about responsiveness and consistency. For critical software, adding in legal liability for one's work creates the quality incentive that's lacking in most professional roles, while retaining the accountability that we can't expect of volunteers.
I agree completely — the lack of proper professional licensing around working on what has become critical infrastructure astounds me. But even more so is the pushback I feel from within the field! It isn’t that the pushback isn’t understandable; its more that its disappointing.
