The thing is, that the game started without NTR, it never said that NTR was going to be another of the fetishes, and it was unavoidable to progress the story.
It's like if you play a NTR game only, it goes for many updates and then in one update the mc gets an harem, would it be ok for you that like NTR ad was playing a NTR game? same happened here, it was grind to see scenes and in the new update out of nowhere rape and NTR.
Even if dev said before the scene that it was NTR and you can opt for not seeing it, it is unavoidable NTR in a game that in no momment said that it will have NTR nor rape.
If it was tagged as such since first release, even in future tags, or the NTR was avoidable it wouldn't get that backslash, but the thing is, it didn't have it and the game is from 2018, so the dev had time to say that in the future there would be unavoidables NTR scenes, but if she said that she would have lose some or many of her supporters so...