I don't follow the genre, but I heard that apparently Steam is also very inconsistent in terms of banning visual novels. And the fans seem to be pretty dedicated to them, so you have an example right there.
I'm personally all for "everything goes", since the adults only settings exist, which might as well double as "disturbing content" filter. At the same time, it's Valve's choice what they want to host, and I don't know a good balance of "reputation vs freedom", which they realistically have to keep.
Despite common sense I bought The Hundred Line at launch, but thankfully it is indeed a very solid game. To the point I spent 25 hours playing it over 3 days. It's more or less a Danganronpa game, so it might be too cringy for some people, but having gained enough tolerance to those things it's wonderful. Probably better than DR, but it's apples and oranges in some aspects.
One "problem" is that the game is really easy, and the whole SRPG part is mostly to enchance the story. It's still really fun, I think that like with Kirby they intentionally wanted a game that anyone can approach. And though I'm just getting started it also does indeed appear to have 100 endings, I ended up on the romance route from my first set of decisions...