More generally it comes back to the right to repair. We operate in this perverse economy where we lack a meaningful right to repair in the digital age because understanding on the subject is so scarce, but I personally believe in a strong consumer right to repair, and in a post-IP world that would include a requirement to disclose source of software - in practical terms, so the owner of the tractor can fix bugs in the tractors computer, but in general so anyone purchasing software - or just goods of any kind - should have the right to understand what it is and how it works.

Its one of the defined software freedoms of the FSF, after all, and its fundamentally why software freedom is advocated for, but it absolutely doesn't need copyright to be enshrined in law.