First of all, lets be clear: I was responding directly to your statement that one is not required to explain themselves (perhaps you didn't realize I'm not the same person you originally responded to). One's offense does not necessarily require others to change their behavior. To do this requires that you explain how their behavior conflicts with their own stated goals: e.g. to be a good person, or in this case to attract more women to the field.
On the other hand, it is certainly the civil thing to do to avoid causing offense when in public, especially in a professional setting. However, there is still a question of how much one is required to alter their behavior to avoid causing offense. This is why explain the cause of offense is very helpful.