It's clear that leftists always believe in a fixed pie. Any increase for one comes out of a decrease for another. Hence the obsession with doling it out "fairly." Sometimes called the daddy mindset of wealth; if daddy gives your big sister a bigger allowance, that means there's less allowance available for you.
Since it's so reliable it must be an inherent trait of leftism.
Why is it inherent? I'm not even sure where to begin looking. Something something creation is impossible, only destruction? Wat?