In this case, the answer is: because, in my opinion, the developers themselves are playing with this fetish and repeatedly dangling this carrot in front of the players. No matter what the two developers keep writing, that there will be no incest because Patreon prohibits it or they don't like this topic, images keep popping up that keep this topic alive.
I think it's a malicious and humorous game that the developers are playing here. It serves as advertising, but it's also fun for the two of them to play with us consumers over and over again.
Apart from the fact that many people infer from the constellation that Edwin's mother once made porn that this is a prerequisite for this woman's low moral standards, in reality it is only meant to be an explanation for why Edwin is portrayed as the character he is.
I don't like playing devil's advocate, especially since TD and GIL are perfectly able to speak for themselves... However, the malice here is entirely in the eye of the beholder. Since TD and GIL stated they don't like and are not interested in incest themes, assuming they are lying and portraying them as mustache-twirling villains playing with the poor incest-loving players' hearts is hyperbolic at best and disingenuous at worst.
First of all, one of the main premises of the game is "Edwin discovers in the worst way possible that his mother was a porn actress - via her reel tapes. This shapes his character and his formative years in a twisted way, and still does it to this day, because the ideal image of his mother he has clashes with reality". Now, with such a premise, you could write the story in two ways: with or without incest. TD and GIL choose the latter because of their own preferences and tastes. That's all there is to it. Saying that the premise
implies the need to write incest in the story is patently incorrect, since themes can be simply adjacent, not overlapping.
Then there's the second premise: the Pale Carnations club. Edwin comes in contact with the girls working there - and a parallel emerges. The girl are prostitutes, but what of his mother then? Was his mother prostituting herself, as they do? As the story progresses, themes blur again, but they do because they are resonant - adding incest to the mix would derail the plot entirely. Maybe it would be viable if the relationship between Edwin and his mother were the only theme; but we're talking of a completely different game.
Now, you could argue that there is no need to show Victoria's reels in game to the player, and insist so much on them. But the fact is, seeing the sex scenes with Victoria adds to the viscerality of the theme, and contribute to make Edwin's dilemma more explicit and poignant. If Edwin (and the player by extension) imagine Victoria as a saintess who was forced to debase herself for her son's sake, seeing her
enjoying sex on tape is a gut punch - and a quick text description of the act wouldn't have the same effect.
All in all, realizing that other people taste differs from yours, and coping with the fact without any misplaced sense of entitlement, is what a rational adult person should do. TD and GIL may like portraying milfs having sex, and not like incest in the mix altogether. If one likes incest, I understand they'd like more games with the same themes, but painting the rest of the world as malicious towards them is infantile.
