Do you actually expect someone with those views to treat you fairly, though? I mean, I'm sure it's not impossible that this guy could leave his opinions at the door and fairly evaluate your performance, and evaluate you for promotion. But I certainly wouldn't expect that to be the case. You claim to have had such a manager once, so I won't deny your experience, but I doubt your experience is typical in that sort of situation.
> Outcomes are the evidence.
Yes! This is something I wish more people would focus on. Outcomes are what matter. That doesn't mean the ends justify the means, but it does mean that we should be taking actions not because they make us feel good (usually only temporarily), but because they are likely to give us the best outcomes.
Regardless, I really don't think most women are going to experience great outcomes with a misogynist boss.
Outcomes are the evidence. I am not interested in your or your company's social media statements. I'm interested in whether people who are underrepresented in the field can succeed at your company and whether you treat people like me fairly. This is obvious self-interest on my part, just like engaging in paid labor in the first place.
"People leave managers, not companies." I think this is the most appropriate cliche to apply to the Basecamp story.