Unlike Nobles, who have money to waste and stuff to enjoy, them having niche fetishes & interests wouldn't be that surprising.
But those bandits aren't rich nobles, they are apparently former villagers with most likely normal sexual interests. So the likelihood of any of them being interested in a feminine boy is very low. And in such a case, what would those bandits even do with a boy like that?
The common norm would be for them to kill him instead of capturing him.
Well, as you can see in other panels, none of the women in the room didn't really try to cover themselves that much either, so how that girl wasn't covering her chest area doesn't hold much.
Similarly, we have seen many flat-chested women already, so there really isn't much proof in that fact either.
And there has been no mention of those women being taken from some slave trader or where meant to be sold to one.
Those bandits kidnapped those women from nearby area and kept them as their playthings.
If they were meant to be merchandise, then they wouldn't have kept them in such poor condition nor allow one to die either.
Even if the Bandits didn't have a fetish for feminine boys, they could have planned to sell him off to someone at some point, only the Author would know.
I brought up the fact that she never covered her chest because you wrote this:
"There is also the fact that if she was actually a boy, she wouldn't have covered her chest area.
No village boy covers chest area like a girl/woman."
MC didn't interrogate any of the bandits, and the bandits haven't had much screen-time. Yes, we know they kidnapped women for sexual pleasure because men holed up for very long need sexual outlet, - the leader's words, - but we only know that much because that's what the bandit leader managed to say before being killed.
We also know that the women of that abandoned village were taken as pleasure slaves for the recruited soldiers in the war, so slavery does exist in some extent, if only during war-time, which still leaves a chance for selling off kidnapped women.
As for your claim that they wouldn't have kept the women in such poor conditions, not allowed them to die, only the last part is semi-accurate. In the many isekai or fantasy manga I have read, there have often been bandits or slave traders that deal with poor-quality slaves in black market slave trade, often comprising of illegally kidnapped women and/or children, and the health of the slaves have been anything from healthy and pristine to sickly skin and bones. Shield Hero is the first example that pops to mind right now.
On the topic of "letting one die," the woman that was on her death-bed was the nun they had captured, tortured, and made to tell them where they had been, they were likely only that harsh with her because they had a goal in mind other than rape, and she was stubbornly keeping shut about the information, both reasons why they would be harsher with her than the others. And then there's the fact that they had a stockpile of quality healing potions, who's to say they wouldn't have used one of them on her later, if the MC hadn't killed them all?
Edit:
I just remembered the one girl that actually died, I don't know the details around her death, but I wouldn't be surprised if she simply couldn't handle the trauma of being raped and used as a plaything, so she kind of just died from trauma and fear.
and MC-kun, have you forgotten that you’ve already wiped them all out? who else do you want to take revenge on? their corpses?
