It compares the existing system with an hypothetical system. Means, people will project their current suffering onto the former while projecting their hopes and dreams on the latter. This screws the results in a major way. If this proves anything it is the profoundness of the "grass is greener on the other site" effect.
Also, I don't think casting a plethora of political, social and ecological phenomena onto some kind of hypothetical binary switch is gonna provide any valuable insight. Also also, especially in the US "socialism" is used to describe things that an European would see as some kind of base condition, like affordable dentists, while it's also serving as the description of the politics of thoroughly fucked up countries. This gives the word very little substance.
I'm a bit disappointed that this kind of "here are some numbers: 36, 1, 0.64" kind of article gains this much traction on HN...
Edit: grammar