@N2O
Mmm... Well, I honestly do agree that it's rather creepy how much that sort of gag is abused in japanese media so it can be pretty uncomfortable when the suspension of disbelief breaks down.
Although as far as something that might satisfy you more, I could add that Japanese culture is externally very, very tight and restrained on emotions and showcase of their feelings, while internally being quite heavily judgemental.
The first trait is what produces these stories, which are meant to have a very "childish" tone to them in how exaggerated things are, and holding to that low standard they don't give a flying fuck about the implications of what may be put on paper, because it's just meant to be humorous material no matter what their culture might tell them. So... yeah, this stuff really is like potato chips. Never meant to be something to savor, but to munch on to pass time.
The second trait is a bit more relevant to this story, however. Japanese people can be really spiteful and petty towards foreigners/outsiders, and you might have heard of that one before because it's really no joke. It is a culture that was soaked in isolationism during it's very, very, veeery long history. In this case, you can see that kind of mentality in the villagers, applied doubly so because hey, they are literally not humans, so time for an extra dose of racism!
Well, as much as it sucks, I guess the extra depth is apppreciated. The story of trust being won and shared is one that stands out more over a dark background of spite. How much darkness in a story is too much is a more subjective question for each reader, but for this one yeah it's meant to look as uncomfortable of a situation as it does.
EDIT: Wew, went into a bit of a ramble here, and I'm not sure I even made my point properly! Well, tl;dr this kind of dark shit is usually meant to be funny because it's exaggerated. Yep, that's the whole reason. In this case it's a bit more interesting because it makes sense with the tale, but usually? Nope, that's the whole depth of the situation.