I've been giving this a lot of thought.
I think I am a little jaded about the impact of marching (this day in age). I believe there are other productive ways I can both make a difference and support women's rights and be a presence. Being on the logistics side of preparing for and managing these large-scale events makes me realize that if you're not also an active supporter of the cause at hand, the people on the other side of the fence aren't exactly saying "oh, hey! Look at all of these people supporting something... they must be on to something, I think I'll listen to their message." Instead, they get more annoyed and bothered that "these people are screwing up my routine, screw them" and it can almost be counterproductive to moving things forward if they weren't already moving that direction. I also don't like the idea of all the opportunists turning the event into something it's not, and multiple credible threats towards an event don't exactly inspire confidence in putting myself into a crowd.
...all of that said, I feel kind of like a coward for saying all of that and recognize my privilege for being able to feel ambivalence. I believe that 10 years from now, I would regret not being part of it. I just generally wonder if protests/marches are the most effective way to move an agenda.