I don't think anyone's arguing for the certification of every software developer. Just those who wish to become a professional engineer. A software engineer will then work on such projects and may even be the one to sign-off on it. They will be held to a higher account and be expected to produce robust, safe systems. All the things that come along with being a professional engineer. And just as it is in other fields, the majority of those employed are not engineers and will work on other projects. We're not talking about anything novel here; the approach would be similar to that of any other professional engineer.
But currently there is no organization offering such an accreditation. Why? Because no organization can credibly claim they can certify who is a "Certified Software Engineer". Maybe somebody should. Maybe the universities should get together and devise such a program and accreditation. It is still a new field.
Indeed. Those interested in such a career would have something to pursue and, at completion, may refer to themself as engineer. For the rest of us we have other job titles to describe what we do (software developer, code monkey, etc.).
But that's true for many other manufactured items as well, and the manufacturer of the product that ends up in the hand of the customer ends up assuming most of the responsibility, since they had the opportunity to test the product fully assembled.