I think some people have an inherent need to gain influence. To have power over others, tell them what to do. Due to monopolization and centralization, there are fewer and fewer spots to do it in a constructive way (found your own company?).

Except if you claim that you're offended, you're suddenly given the right to control what others say. If you claim that you are fighting racism/sexism/etc, you're shielded from 90% of critique. So this "safe haven" has attracted all kinds of opportunists that just enjoy attacking others to feel better about themselves.

Look at your typical BLM protestors. It's not Black doctors protesting against being treated differently from White doctors. It's unhappy people from both races that have found an uncriticizable cause to justify their own disappointment in life.