alt Hacker News> here in America, sometimes CEOs get shot as well
No, they don't. The UnitedHealth dude who got shot had a CEO title, but Thompson was ultimately a middle manager.
The actual CEO of UnitedHealth Group–the one who signs off on its financial statements and fields quarterly calls–and the billionaire owners were fine. Which explains, in part, why nothing changed after the shooting.
You're implying that something would have changed if a different person was shot instead. Structural problems don't work like that. The individual players have the incentives created for them by the system. To change it you need to change the game, not the players.