1. Tragedy of the Commons (https://en.wikipedia.org/wiki/Tragedy_of_the_commons) / Bystander Effect (https://en.wikipedia.org/wiki/Bystander_effect)
2. In practice, the risk of introducing a breakage probably makes upstream averse to refactoring for aesthetics alone; you’d need to prove that there’s a functional bug. But of course, you’re less likely to notice a functional bug if the aesthetic is so bad you can’t follow the code. And when people need a new feature, that will get shoehorned in while changing as little code as possible, because nobody fully understands why everything is there. Especially when execution speed is a potential attack vector.
So maybe shades of the trolley problem too - people would rather passively let multiple bugs exist, than be actively responsible for introducing one.