Emiko had plenty of chance to escape but decided to sneak back into her prison every night. She fucked around and found out. She is dead because she and the MC were stupid. its admirable for a dev to write a story were acting stupid results in consequences.
this is entirely moot, as it was Zimons decision to write it like that. "Emiko" and our "MC" don't have wills of their own.
the "Disposable Love Interest" trope is common and can be used well, as in cases like Spike Spiegel, or the Injustice timeline Superman. but those and most good examples have a lot more going into them and had to work to make it pay off.
in this situation it is a terrible fit regarding the trope itself. a harem porn game is already a hard sell to pull off a LI's death in, but this? it's rage bait at best. there are dozens of tropes to instigate character growth, but the point of the tag is essentially "collect all the wives," and yet we're told in a power oriented plot line "oh except her....you can't have
THAT cat girl."
it is entirely contrarian to the goal. you could equate it to trying to add a hitch to the back of a VW Beetle. is it on there? yes? are you towing something with it? not advisable.
what's more it's set up to show her on the roster and make her "seem achievable" so to speak. intro quest, unique character design, everything needed to imply she's part of the harem. instead we get a bloody end, and a preferment reminder of it.
...it isn't motivating, it's demoralizing. a permanent reminder of failure. a carrot and stick that lacks the carrot. we wanted a cute cat to take home and got a carnival prize goldfish.
but yeah, main point here is that blaming a character for dumb behaviour resulting in death comes with the flaw that Zimon literally wrote it all that way. he created the problem itself and up until the management shift was running the game solo. unless the new staff pull of a hail mary here, Emiko's death lies solely on Zimon's writing. personally if we're gonna stick with overused tropes I am still holding out hope for some kinda of less volatile Lazerus Pit ordeal, because while I want our cat back, we're gonna need a little less brain damage then that one version of Jason Todd they pulled outta the Raz Al-Pool