It’s just pointing out that your position isn’t consistent and seems to be related to how close the subject is to your own experience, while providing examples of the phenomenon of turning a derogatory generalization into a broadly understood concept that isn’t necessarily attached to its root. (Barbarian is a fun one since the word was making fun of the way foreigners talked. I don’t know of a direct contemporary comparison because people would rightfully point out that “chingchonger” is wildly offensive.) “Mansplaining” is a behavior specifically called out as a self-assured-man-assumes-ignorance-in-woman-and-condescendingly-explains-a-thing. It’s not just dudes talking, it’s not all men, and it doesn’t hurt men that the behavior is identified. Mansplaining is a particular tone and context, it’s hyper-specific language critical of one facet of patriarchal dominance and the assumed value of masculinity.