Kathleen Hanna is fucking awesome; and I missed out on a lot of good shit in the 90s.
The riot grrrl movement was an artistic expression of feminism, led by women who looked around and saw that they're not treated or even viewed the same in society. They utilized the labels and extremes that society placed on them and transformed them into rhetorical and visual weapons against things like sexism, violence against women, and gender inequality. They gave a creative voice to the anger and frustration that many women have, empowering them as well as calling out a society and culture that often relegates women to the periphery.
Everyone doesn't see the world the way you do. Everyone has different experiences and outlooks and you shouldn't necessarily give up on a relationship or friendship simply because you're not always on the same page. By being a part of someone's life, even if you have really serious political, social, or religious disagreements, you can help that person grow and eventually see things differently. If you take away an arguably positive influence on their life, you're not doing them any favours, especially if you really care about them.
Changing minds and social structures takes time. Things like racism, sexism, gender and sexuality inequality don't disappear overnight. Each generation needs radical movements to help build on the progressive momentum of the previous generation. Be a part of that any way you can.
It's important to be vocal about these kinds if issues. If you're educated about these issues and keep silent, that silence = consent. Confront discrimination and inequality. And if you find yourself in a relatively privileged position (e.g., being a white male), be a good ally—stand in solidarity with whomever you're fighting with while at the same time giving people and groups their space when they need it. Don't take it personally. Even if you feel like you're not a threat and are 100% on their side, there may be times and places where they'll feel more comfortable talking about certain things without you there, or else would like to speak for themselves as a member of particular identity group.