I'll tell you my theory, and some of you aren't going to like it.
Twitter has convinced a lot of us that online activism is the same thing as real-world activism, when the reality could not be further from the truth.
Out there, we are pushed by algorithms into ever tighter echo-chambers of like minds. We follow those who agree with us, and block anyone who doesn't. We think we're convincing people, when all we're really doing is convincing ourselves.