I actually think that the FOSS movement and licensing is really progressive in this space.
This thing comes with NO Warranty etc is really great because you own the risk of the systems you build. If only that got surfaced more to the users so they realized that a T&C page isn't really protection for anything.
Rather than force devs to use formal methods, I'd really like it if software got to the point where regulators and insurers demand that we treat personal information like radioactive waste and try and handle the least amount possible.
I don't think professional liability would require all developers to use formal methods any more than it would require all practicing software developers to become licensed engineers.
It may require companies to hire a licensed engineer to sign off on projects and it could require those engineers to be insured so they may want to use formal methods on a risky project to keep their rates down.
The end result, I think, is the same: pressure to do better by the standards of the state of the art and not skimp on privacy and security.
Rather than force devs to use formal methods, I'd really like it if software got to the point where regulators and insurers demand that we treat personal information like radioactive waste and try and handle the least amount possible.