I think they actually had too many writers before. Not long ago their was a bit of drama on their discord about the Shackbang writer getting fired and now it looks as though the same has happened to the person that wrote the Mia games. Who knows, maybe they're better off pivoting towards Unreal games where story doesn't need to be as important.
Well, the shackbang writing was crap. Mia I found ok, but S2 took a long time to complete, so maybe he was just lazy, who knows.
I can only repeat what they said, I have no idea if it's true or not. And in the end they kept adding wallpapers and stuff to their games, but nothing storywise.
ps:
pivoting towards Unreal games where story doesn't need to be as important
I strongly disagree with your opinion about story and 3D
For me, the story and game design are the most important aspect, no matter if it's presented in 2D or 3D.
Free moving camera during sex scenes? It's a nice to have, but if the game is boring I will never see it.
There are great 3D adventure games out there with great stories, just when it comes to the adult sector, people still go the easy 2D way. There are enough 3D sex simulators (they existed long before prerendered graphical novels), but I don't play these, they are just curiosities.