It is hard to follow her point because her behavior undercuts it.
If it is wrong to perform on Broadway when there are people like Scott Rudin working there, why did she wait so long to leave? It is believable that someone could have a change of heart and understanding deepens, but she never explains why she feels differently now than she did when she opened MR.
And she seems to feel that her action will make a difference, but is unclear how. Does she want other to leave? Does she want a consumer boycott? Or does she feel that her choice will be all that is needed?