Why not? There are only two redresses against elites who don't abide by a social contract: the law & courts, and physical violence. The courts are much preferable, but legislators now serve those elites rather than the public, and the courts are impotent or unwilling to use what power remains with them. What's left but physical violence to either dissuade or punish?

The specific stigma against physical violence (and not against other types, even for cumulatively worse actions) strikes me as very self-serving, an instance of "the law forbids both rich and poor to sleep under a bridge." It's increasingly the only remedy available to everyday people, and the mad acceleration of government capture by elites in the last decade is making murder and rioting inevitable, at least as long as ordinary people still feel they should have some power.

Any sort of violence is bad, singling out physical violence as uniquely bad gives misbehaving elites impunity.