First of all, anything that helps draw attention to a worthy cause is a good thing, provided it doesn't hurt others. I can't for the life of me see how a woman deciding not to wear a bra hurts another person.
While some may take things too far, those people would do so, no matter the subject matter. The cause is not the problem. It's people and either their own indiscretions or their own bigotry toward women being themselves (who says we always have to wear a bra - the things are wildly uncomfortable and also unhealthy and unnatural).
Look, the whole internet is talking about this issue, correct? That's a whole lot of breast cancer awareness right there -- and that's a really good thing. So many people (and not just women) die or have serious life-altering issues due to breast cancer. The more we can get people thinking about this, the better, regardless of how we do it.
Let's stop nitpicking at the little things, like whether someone has on a bra or not, and start helping each other. If you're so upset, throw that energy into supporting breast cancer research or another worthy cause.
The less time we spend on fighting, the more time we have to actually do something that matters.
Wear a bra or don't. Who cares?
What we should care about is helping others. Are you doing your part?