This is one those stories where most people won't like it,which is fine, but if the story maintains, overtime the score will go up. Easy examples are the hyper violent revenge mangas, I remember they were at 5 & 6s and every comment was about how edgy they, eventually that wave passed and now they are high 7s and 8s.
From what I have read this has the potential to do same, but it is most certainly not assured. I think the tipping point here is what comes after the current arc, and who will take the place of the antagonist once they are defeated.