Voodoo Lab Pedal Power Cable PPBAT

I bought three of these a while ago, and just tried them out in my home studio. The concept is very convenient for me, as I'm always swapping out pedals and I can't possible keep batteries in them all.
But they didn't work. None of the three.
After looking at the comments on this site, I flipped the polarity. They work fine. I can re-solder them, but how is it that they are wired incorrectly? All three? Quality control?

Really disappointed because the polarities are reversed. I had to reverse the wires.

I should have read the reviews before picking this item up.
It does indeed have switched polarities, and thus - not useable.