I've fixed my own before, and I am convinced the error is simply in the design of the little spring extension. It has ~180-degree loops at the ends - if they were 270 degree loops, it wouldn't pop off and the little stopper tab on the side would limit the rise of the wiper arm. I even asked for some quotes on having new custom "extensions" made but guess my requests were for too small an order to get anyone's attention.
The "Stopper tab" on mine was also so shallow that it didn't stop the rise of the arm.