Probably because GGP’s comment reflects a narrow, unfavorable, and extreme view of reality

> Real life is a rigged game where rules are not enforced

Even in the United States, there are plenty of stupid and non-stupid rules that people are forced to follow in order to “play the game”. There are also plenty of rules that only apply to certain groups. There are also plenty of people who don’t play the game at all.

Maybe if GGP weren’t so extreme and negatively one-sided with his view, then it’d come off as less pessimistic and more critical.

I would probably say "cynical" rather than "pessimistic". I would also say that it does not actually reflect reality. Reality is also not the exact opposite of this perspective. Reality simply doesn't bear reduction to either "everything is a rigged game" or "everything is fair"; it's more complicated than that.

pessimistic and realistic are not mutually exclusive (unfortunately). You can understand reality without accepting it.