It makes you *look* like you care, but really, you only care about yourself and your more immediate in-group
Outrage expressed "on behalf of the victim of [a perceived] moral violation" is often thought of as "a prosocial emotion" rooted in "a desire to restore justice by fighting on behalf of the victimized," explain Bowdoin psychology professor Zachary Rothschild and University of Southern Mississippi psychology professor Lucas A. Keefer in the latest edition of Motivation and Emotion. Yet this conventional construction — moral outrage as the purview of the especially righteous — is "called into question" by research on guilt, they say.
Feelings of guilt are a direct threat to one's sense that they are a moral person and, accordingly, research on guilt finds that this emotion elicits strategies aimed at alleviating guilt that do not always involve undoing one's actions. Furthermore, research shows that individuals respond to reminders of their group's moral culpability with feelings of outrage at third-party harm-doing. These findings suggest that feelings of moral outrage, long thought to be grounded solely in concerns with maintaining justice, may sometimes reflect efforts to maintain a moral identity.
Comment: This is why conservatives, who tend to have more moral taste buds than liberals/lefties, just don't scream and holler on the streets as much. They do care about issues, but they're not as narcissistic and have too little time on their hands because they're busy actually doing caring things for friends, family, community and so on.
See also: