Where to start.
I think "ban bossy" is, overall, a positive message to put out there. It is, or at least ought to be, an attempt to make people more aware of the fact that uncompromising men are often respected for being uncompromising, but uncompromising women are demonized for it. "Bossy" is disproportionately applied to women in authority positions. I've had to reconcile my feminism with my anti-authoritarianism because I tend to mock and deride any authority figure, and have been told that I'm a sexist for mocking and deriding female authority figures. I can understand why some women might get a chip on their shoulder for this - I think the same thing happens to short men as well. When they get in a position of authority and aren't taken seriously, they assume it's because of their height, and it's hard to blame them for this assumption. They have no way of knowing that the person not taking them seriously doesn't take ANY authority figure seriously - and there are even people who CLAIM not to take any authority figure seriously, but in practice defer to some authority figures and not others, because some targets are just easier. These people are in fact being discriminatory in their practices but they might not notice it. I have been guilty of this. We are often blind to our own faults, and we are especially often blind to the ways in which we don't live up to our own moral standards.
I don't like the word "ban," because it sounds authoritarian, and I think that's a shame. I do think the trend of reducing complex social issues to a freaking hashtag that people either stand WITH or AGAINST is not a positive development and doesn't promote consciousness-raising among the people who are most ignorant of the issue. And I think that, from an anti-authoritarian perspective, it's important obviously to not automatically dismiss any criticism of female authority figures. So I don't exactly stand with "ban bossy." But I am closer to supporting it than I am to opposing it, even as an anti-authoritarian anarchist who is fundamentally against 'bosses.' Because I know that they are not REALLY trying to "ban" the word. No one is talking about actually punishing people who use the word. If anyone is I'm against that obviously.
What I would suggest is that if you get labeled a sexist for criticising a woman it's probably because you sound like one. Don't get defensive. Instead, try to work past the misunderstanding. Recognize that human beings instinctively categorize people and lump them together, and that we do this because it is useful more often than not. Demonstrate that you understand that some people DO exactly the thing you're accused of, and ask yourself if you haven't yet said anything to distinguish yourself from the legion of shitheads who say the same things you do. If your boss is a bossy woman, she has had to deal with sexist jerks her whole life. She doesn't have any reason to believe that you're not one of them if you start sounding like one. She may not be capable of understanding this either (because bossy people don't like admitting they are wrong). Recognize that you can't always change one person's mind or make them understand.
edit: It's also clear that there ARE some men who view gaming as a "male space" and believe that feminists want to destroy all "male space" while sanctifying and preserving female spaces. I can sympathize but as a somewhat gender-variant male who has always been deeply, deeply uncomfortable with "male space," I kind of want to blow the doors off the clubhouse. I don't like the way that 90% of my guy friends talk about women or talk to women, and most of these guys would think of themselves as anti-sexist.
