I mean… “Cast of darker skinned characters” isn’t really accurate unless you’re including the alien characters like the Galra. Until Season 7, there were only two major characters darker than Lance, Hunk and Allura, both of whom are shipped as well, although I agree that Hunk is under-appreciated (but again, that’s in part because the story itself treated him so awfully)…

Out of all the fetishizing things I’ve seen in the Voltron fandom, Shiro being Japanese is one of the least common fetish fuel elements I’ve noticed in fanarts or fanfic, significantly far behind the whole furry elements with the Galra or Lance’s “Latin lover” treatment…

…“dark skinned boy around the same age”… I mean, would you prefer fans to ship him with someone not at all around the same age? What’s the point of bringing this up?

I guess my response to this ask just boils down to: Do you spend time policing the ships, behaviors, and posts of men who fetishize female characters? Of dudes who watch hentai? Of guys who draw women with ridiculously disproportionate breasts and thighs? Because if you aren’t out there protesting the treatment of female fictional characters by men (or I guess anyone who fetishizes women, sex/gender regardless), then you probably shouldn’t be judging the shipping of female fans either.
¯_(ツ)_/¯

People ship for an uncountable number of reasons and in an uncountable number of ways. Some people certainly are excessive and ship for their own romantic or sexual gratification, but just as many others–in fact I would argue far more–ship genuinely from a love of the characters and their interactions, and are capable of respectfully shipping whatever pairings they like without infringing on the feelings, rights, or lifestyles of real human beings. This isn’t like… 2004 anymore. At this point I can probably say that most (not all but most) fangirls have at least gotten themselves past the point of running around screaming in public about how they “love the yaoizzzz ohemgee”…

Fetishizing can certainly be harmful when it crosses the line from fictional into reality; no one can or should be debating that. But I’d caution that everyone who feels it’s within their right to judge women who find relationships between male fictional characters sexy to ask themselves whether they hold fetishizing men (and fetishized heterosexual ships catering primarily to male fans) to the same standard.

If not, that’s probably a pretty good sign that’s what bothering you isn’t actually the shipping, but the mere fact that women dared to talk about something they found sexy, which is a wholleeee other problem.