It is a standard trope of fiction that people often get angry when they suffer life outcomes well below what they see as their justified expectations. Such sore losers are tempted to retaliate against the individuals and institutions they blame for their loss, causing increasing damage until others agree to fix the unfairness.
Most outcomes, like income or fame, are distributed with mean outcomes well above median outcomes. As a result, well over half of everyone gets an outcome below what that they could have reasonably expected. So if this sore loser trope were true, there’d be a whole lot of angry folks causing damage. Maybe even most people would be this angry. Hard to see how civilization could function here. This scenario is often hoped-for by those who seek dramatic revolutions to fix large scale social injustices.
Actually, however, even though most people might plausibly see themselves as unfairly assigned to be losers, few become angry enough to cause much damage. Oh most people will have resentments and complaints, and this may lead on occasion to mild destruction, but most people are mostly peacefully. In the words of the old song, while they may not get what they want, they mostly get what they need.
Not only do most people achieve much less than the average outcomes, they achieve far less than the average outcomes that they see in media and fiction. Furthermore, most people eventually realize that the world is often quite hypocritical about the qualities it rewards. That is, early in life people are told that certain admired types of efforts and qualities are the ones with the best chance to lead to high outcomes. But later people learn that in fact that other less cooperative or fair strategies are often rewarded more. They may thus reasonably conclude that the game was rigged, and that they failed in part because they were fooled for too long.
Given all this, we should be somewhat surprised, and quite grateful, to live in such a calm world. Most people fall below the standard of success set by average outcomes, and far below that set by typical media-visible outcomes. And they learn that their losses are caused in part by winners taking illicit strategies and lying to them about the rewards to admired strategies. Yet contrary to the common fictional trope, this does not induce them to angrily try to burn down our shared house of civilization.
So dear mostly-calm near-median person, I respectfully salute you. Without you and your stoic acceptance, civilization would not be possible. Perhaps I should salute men a bit more, as they are more prone to violent anger, and suffer higher variance and thus higher mean to median outcome ratios. And perhaps the old a bit more too, as they see more of the world’s hypocrisy, and can hope much less for success via big future reversals. But mostly, I salute you all. Humans are indeed amazing creatures.
I do suspect that Loss aversion is a big reason why people don't take enough angry action.
Given your terminology, "stoically" is, at best, unnecessary and, at worse, misleading in describing some of those who are accepting.