There's another second order effect here that is worth naming. Primarily, if we broadly point to people like Alice as noble and brave, many of those who want to be pointed at as noble and brave will act like Alice (Goodhart's Law). This creates a kind of perverse incentive, where people want to be activists first, and then think about what cause to fight for second. Furthermore, if one's identity is partially focused on activism, there's a sort of unconscious incentive that can arise in some people where they actually don't want their issue to be resolved...
Agreed on the default, but I would argue the mechanism is slightly different. Norms of kindness are sustained by an equilibrium where most people expect most others to comply, and enforcement (formal or social) handles the margin that doesn't. But that equilibrium has a tipping point: similar to other social network effects, desperation scales superlinearly with the fraction of already-desperate neighbors, because each defection both signals permission and reduces the enforcement budget. Prolonged disasters either increase the number of defectors or decrea... (read more)