I'll go farther and say that identiy politics are an expression of a crisis in self-esteem. They validate self-identity, which is not a real identity but the articulation of ego which is a product of how we're nurtured. If you require other's validation to be happy you'll eventually be forced to confront your own self esteem issues. However, if you wrap this up in politics it becomes much easier to dismiss your discomfort as a casualty of a greater cause and excuse the force required to attain happiness at the expense of others.
In this case the white person who we'll call Alex is seeking validation through permission to go to a pubic event. When another person dissents they're scolded, as a child would another for breaking an adults rule. The reprimand clearly disaffected from any direct responsibility or reasoning. Alex is seeking validation at the expense of those he seeks it from. He requires1 that they spend their own time and energy to take care of his emotional needs.
1 if they don't he'll probably join the alt-right.