alt Hacker NewsWe would call it "a serious code violation." It's prohibited in the NEC and always has been, it's objectively less safe.
From what I understand the UK allowed it because of a severe postwar copper shortage and it persists to this day because it's allowed and a bit cheaper.
> From what I understand the UK allowed it because ...
I'd say "severe post-WWII money shortage". After wartime expansion, the global copper industry could physically meet peacetime demands. But the UK was very close to national bankruptcy. And the Luftwaffe had turned an awful lot of their prewar housing into rubble. So - any cost that could be cut, was.