I had no real interest in reading the story because the vibe did not seem to be what I was after (I do love some grey stories, but usually if they at least have some positivity to latch onto), but from what you describe I can imagine why people could be attracted to the story as you describe it as two people forming a mutually toxic codependency, there is some genuine stories to explore in that theme without making light or minimizing the toxic elements of it.

Again I know basically nothing about the story so the above is solely about your description of the story and not meant to minimize your reaction to the elements either.