I don't understand the obsession with the Just World Fallacy on this sub

Just as the title says, I don't the obsession Blue Pillers and a lot of women on this sub have towards the Just World Fallacy argument, and there's multiple reasons why.

Whenever there is a post about "nice guys" one common consensus is that being a nice/good guy by itself is not good enough. It does not compensate for being unattractive or socially awkward. That's usually agreed upon. Yet then other posts pop up about fake nice guys, or comments come up with Blue Pillers claiming if a guy fails it's from some innate misogyny the woman could sense or how fukbois get some eventual comeuppance in the end after going through droves of women like some Disney movie villian ending. There's definitely some form of cognitive dissonance where on the one hand Blue Pillers accept that being nice doesn't just make you attractive but also stuck firmly on the idea that men who fail to get women for a prolonged period of time is due to some moral failing that must have been perceived.

What's the obsession with these Just World ideals? Is the fear that men will stop White Knighting for the fukboi lifestyle, that women will come off as shallow for selecting a guy for looks over personality, or something else?