I think people might be overlooking the incest themes when being confused by or claiming that the dev's family shouldn't have issues
Legality is one thing, the social implications of being involved in porn another, but to the family member of someone making incest content it might be a bit more alarming than if it was just something more vanilla.
I can understand the need for a hiatus (or to even leave the project), especially if you value your family and their feelings towards you.
It's good to see that they may have sorted that stuff out though.
It's strange that most of us live in a world where you could probably write a torture porn screenplay and barely anyone would bat an eye, but have blood related characters get romantically entwined and not vilify it and people start questioning your morals.
Even though incest content isn't really my thing anyway, wanting to be open to my friends and family about what I'm doing is probably the actual main reason I wouldn't want to include incest in any projects I would be a core team member of. I don't personally have a problem with it, I'd just rather avoid having to deal with that particular tin of worms when it comes to justifying my creative choices.
It's probably gotten easier overall after Game of Thrones managed to make Jaime Lannister pretty likeable but my family didn't get that far into that series so I wouldn't have that in my corner.
tldr: I actually feel like family finding out about your incest game is actually one of the better excuses a Patreon game dev has had for why they've disappeared.