It is more of a case of Chinese whispers regarding that particular situation in my understanding – the author didn’t “condemn users” who were clamoring for incest content, he simply responded to those requests he wouldn’t put such thing in his game.
Some people interpreted it the way they did since it serves narrative of having some selective moderation, but if such act counts as moderation and taking stance against, well, you have a screenshot in the very OP of the author also telling the racist asshat that his racist rants are off-topic and another of him posting a meme suggesting such talk to be knocked off. This is about the same level of slap-on-the-wrist not-really-policing.