You can make yourself angry because what others do is not in your own mind or hurts your own interests. People are basically not angry with themselves because of their own mistakes, which is the understanding that anger is to punish themselves with other people's mistakes.

You can help others not to make mistakes, you can watch them step into the abyss, you can also take action to defend your own interests, you can do anything, but you can't be angry. To be angry is to punish yourself with other people's mistakes.