Well, you can see the attraction of it!
Chinese state security (translated): "We enforce an unchangeable IPV6 address (by law) on all devices used inside the Great Firewall and bingo, we can follow everyone, everywhere and log everything they say, do, read and connect to. No hiding behind NAT any more. What's not to like?
The NSA are gonna be soooooo jealous!"
Addresses are dynamic now, but if they force local manufacturers to bake one into the networking stack of each device, how can they refuse? Do it or we shut you down and all your plant are belong to us. And enjoy the re-education hard labour camp.
Practical enforcement is another issue, but the mindset is obvious.