Am I alaone in completely failing to understand what the fuss
is about?
The image is not pornographic, exploitative, illegal or
otherwise
inapropriate for featured picture status.
The image is also not artistically, historically, or
culturally significant, unlike all the other examples you
cited. The only reason it's featured is because it's sexually
arousing to anime fanboys who happen to dominate the culture
of Wikimedia Commons. I don't need to crawl into a semantic
rabbit-hole to defend this observation. I think its obvious to
any reasonable person. If the image would be embarrassing to
pull up in front of a classful of students, it shouldn't be on
the Commons Main Page.