Spanish words ending in "o" are, by default, inclusive. For centuries, it has been a linguistic idiom (not just in Spanish) that references to mixed-sex groups

Spanish words ending in "o" are, by default, inclusive. For centuries, it has been a linguistic idiom (not just in Spanish) that references to mixed-sex groups of people are done in the masculine. Women understood this perfectly and were not slighted by the custom, because it would not lead to an assumption that a group of people were homogeneously male or an assumption that women were "lesser" than men or excluded from the conversation. If a group of people is uniformly female then the feminine declensions can be used, and fluent speakers will easily shift from one to the other based on group composition. It's very much the same sort of situation that we've used words like "mankind" and "peace on Earth, good will towards men" and women have always understood that "men" included them implicitly. It's only recently that women have chosen to take linguistic offense and rise up and complicate the language in search of manufactured equity.