Sure having blameless postmortems would be amazing, but I think the informal process I described is probably the closest you will get to it. The reason being that any given subfield can't make this decision in isolation, because the people to who it matters (funding agencies, faculty search committees, journal editors to a degree) are not part of the field, and when they see such a 'blameless postmortem' they will think 'whoa, this person really messed up, we'd better stay away'.

Maybe I am wrong though, and a better culture is possible, like the shift to preprints has happened in a lot of fields and was probably previously unthinkable. So good on you for taking an idealistic stance, I am probably just being grumpy. That being said, whatever culture changes may be beneficial, I stand by my original point that simply dumping code and model alongside the paper is not unambiguously good and may even obscure problems.