Everyone is semi-pissed at how willingly incompetent the MC is…
Guys, this isn’t actually a shonen.
Guys this is a COMEDY. Read it like that and this reads so much better. Even if the official genre isn’t one.
It's a comedy insofar as the main character is invincible and superpowered, but is oblivious to this and is also a complete moron.
The
setting she's in is very much
not a comedy. Civilization is in active danger, people have already died on-screen, and every other character is acting to ends that indicate real peril and drama.
The single exclusion is Kinoko, and
all of the comedic elements are built around maintaining her idiocy and naivety at all costs.
And we even have an actual stated goal from the main character herself - she wants to
move beyond the very thing that is injecting any sense of comedy into the series at all. So what happens once that occurs? Or, is it allowed to never occur, and the world increasingly bends itself around keeping Kinoko in the dark, no matter how outlandish or contrived the rest of the characters and the setting itself have to behave to make that happen?
Usoyama should
absolutely spill the beans to Kinoko after this, whatever selfish reasons she had for not doing so before. Her own life was put in mortal peril because Kinoko's a moron and is incapable of reading the situation before her, however overt it maybe should appear. If she doesn't say anything, then she's implying that the same situation can arise again because that's less important than Kinoko gaining awareness of herself and her situation.
Kinoko's sister is also complicit, and if she finds out what Kinoko was wrapped up in, that other people died, and still says nothing - then that's another point in the "the world's logic is thrown out in favor of keeping the protagonist's gimmick intact" category.
That absurdity can work, but it works were the stakes aren't so final for the world at large. Looney Tunes gets away with tons of violence because no one perma-dies and everything resets next episode. That sort of comedy doesn't work where the setting can be destroyed and you can't* just have the cast walk off being eaten or having a building dropped on them.