It's an interesting challenge because the device is nominally "under ISP control" but any device located in a customer's home is under the physical control of the customer. The mistrust between the ISP and the customer leads to "trusted" devices where the firmware, including the backup, can be overwritten by the ISP, but then cannot recover if it gets corrupted. And believe me, the corrupt firmware scenario happens a lot due to incompetence.

This is getting attention because it wasn't incompetence this time.

But how does blank, unprovisioned equipment discover a path to its provisioning server? Especially in light of the new "trusted" push, this is an arms race in a market segment such as routers where there isn't any money for high end solutions - only the cheapest option is even considered.

tl;dr: a social and economic problem, likely can't be fixed with a purely technical solution