You can't blame WWG for making scenes with characters that never interacted before. Those were suggested and voted for on his patreon. WWG even made a rule that Ophelia, Cath and Brenna could be used multiple times for Last Chance suggestions, unlike every other character.
He gave the community every opportunity to make more Ophelia if they wanted, but the community didn't vote for it. So again, WWG isn't to blame as he let it up to his members to decide what extra scenes we wanted.
That isn't really a fair point. WWG as the dev is solely responsible for what gets put in the game. Patrons not voting a particular way doesn't preclude him from adding whatever he wants including more Sterling x Ophelia sex scenes. If you add up all the sex scenes in the game, how many were the result of a Patreon vote? I'm guessing not many.
This is, unfortunately, the same problem that plagues most adult VNs, especially incest VNs. Having sex with the mom or some other main love interest is saved for near the end of the game because it's the most obvious and easy thing to do from a writing standpoint. But once you get there, now what? If it's one of the end goals then we are, by definition, now at the end of the game.
NLT somewhat offsets this with booty calls in his games. Lewdlab added sandbox scenes for the same reasons. I wish it were more common to have stories where we could get to the sex scenes with the main love interests closer to the halfway point than 80-90% to the end.