This is true, and for the record, I have no problem with NTR and/or sharing, it isn't something I particularly look for in a game, but I wouldn't refuse to play something just because it has it there.
That said, the Dev only has so much time, so they put in "unpopular" content, even if it is optional, then there is less content for the other branches. If you are going to put in NTR/sharing content, it is best done early that way, those people who like it know what to expect and those people who hate it can ditch the game rather than complaining endlessly in the comments section.