I never understood this policy of Patreon and collective shout, but whatever. As long a game doesn't condone it irl what's the issue? It literally says adult content.
If a game has guns or assassination which is immoral irl Patreon sleeps, but when it comes to incest "damn, won't somebody think of the children?"
Even if I like the taboo, I must admit it, being family members for the sake of being family members isn't good. Yet, this game had a great balance between writing, taboo and drama. The relationships between the characters feel extremely natural and flow great with the flow of the story, and even unironically gives a more human side to the MC, but whatever, who am I to judge.
It really sucks for the dev to be forced to change some of the plot to keep his project alive, while at the same time against his will being forced to make decisions that may sadden his fanbase. Fortunely his fanbase in general is very understandable (being communicative and engaging with his fans also helps of course), but I wouldn't like to be on his shoes when it comes to this specific aspect.