A few years ago, I dropped in at a local garage sale (yard sale) and pottered around for a minute to see if there were any little treasures, when I happened upon a double adapter which caught my attention. Without hesitation, I handed over the cash (just $2) and then placed it on the concrete driveway and stomped on it with my steel cap boot, smashing it into oblivion. The startled householder asked me why I did that and when I explained, he offered me my money back - but I said it was worth the $2 just to know it was never going to be used ever again. (And, yes, I did pick up all the pieces.)
For those of you that might be wondering, it was the same style as the one at the left of this photo, but without the tape.
... and what these three double adapters have in common is that they all reverse the Live and Neutral pins on one side.
Simplicity of construction lead to this - and here is an interior shot of the middle one, so you can see how it came to be.
But all it took for the same construction technique to provide correct pin orientation was a simple layout change...