That's a neat design, so long as when you wire the plug you reassemble it with the teeth intermeshed properly and the blades parallel.
I'm thinking of things like electric jugs and old toasters with flip down sides.
That was common here too, although I wonder whether they were made that way
because switched outlets were common. (Chicken & egg?)
Some British kettles, irons, and so on in the 1940s/1950s came with a big connector on the appliance end which had an integral switch, often a heavier version of the "pushbar" type of switch you could find on lampholders.
At one time MK made a BS1363
plug which had an integral switch. As I recall, it was virtually an extra "layer" inserted between the basic plug base and the cover, making the plug pretty bulky. I think they even did one with a built-in neon indicator too.
Radios also didn't have switches, the reason being that because double pole switches did not exist as part of the volume control potentiometer and it was illegal to have a single pole switch in a portable appliance.
It seems that Australia has been pretty strict on this for a long time. Live-chassis radios and TVs with single-pole switches were very common here, and in those days many were fed via reversible two-pin plugs. In D.C. areas, those in houses fed from the negative pole
had to have set running with the chassis live and, usually therefore, the switch in the neutral.
There were at least some manufacturers here who used potentiometers with double-pole switches though.
