slast:
1. In a modern airliner conducting low-visibility autoland operations, there is already double monitoring to prevent such issues. The PF monitors autoland sequences all the way to landing and rollout. The PM provides an independent, second level of monitoring and decision making.
Since both pilots are already monitoring, there is no need for them to switch roles between PF and PM at DH. In fact PMA might add risk: by taking away both pilots' concentration from monitoring to role switching, at a critical moment.
2. In a modern airliner conducting low-visibility ops using HUD/EVS, there is no inside-outside transition at DH, and so again role-switching at low altitude brings no value to the table.
Let's not do PMA just for the sake of doing it. It doesn't make sense to "force" the use of PMA where it's no longer applicable.
Now, there are a lot of ops (especially regionals) flying equipment with neither autoland nor HUD. For them I agree PMA or a variation of it should be the norm. And in the US at least, this is the case.