I don't agree with your assessment.
I think the developer/writer is attempting more of a heavy lift than many writers of incest or incest-like games attempt. To me, the writer is attempting to more accurately describe/portray a protagonist's inner struggle with the developing relationship with these three girls whom he raised as a father. I'd argue that the reason that they aren't being portrayed as blood relatives is more due to the fact that he's trying to avoid entanglements with Patreon, Steam, etc. and not as a device that would allow the MC to be freed from the "fatherly duty" psychological/emotional responsibility to these girls that would otherwise be present.
Although the game isn't going to be completely true to "real life" where the main character would ultimately reject a sexual relationship with the girls he has raised as his daughters (and is portrayed as raising them with all the love that a "real" father would give to his "real" daughters), we all know that sex is on the horizon. I'll echo something that a lot of people have said on this board and say that it's a nice change to not have a father character who is an amoral scumbag who manipulates and defiles his daughters.
So, I wouldn't say that the MC is an unlikeable cuck (although you're certainly not the first to voice this complaint). I'd say that the author is trying to thread a needle where a conflicted MC wrestles with the growing sexual attraction between him and these three young girls given that he has filled the role of father figure (quite well, as it's been presented) for so many years but ultimately gives in to temptation and fucks them all silly.
As far as whether the MC is going to embark on some escapade of kinky sex, it's still too early in the slow burn to be able to say with any kind of metaphysical certitude; however, given the author's focus on the MC's wrestling with the growing sexual attraction and how that conflicts with the role he has played in these girls' lives, I wouldn't see it as any kind of guarantee that he's going to end up pissing in their mouths while dressed as the Joker.
So yeah, I suppose if you're looking for a story where an MC asserts his masculinity by treating the female characters like objects, then this might not be the read that you are looking for.
I think the author is actually trying to explore some kind of psychological/emotional struggle in the MCs mind. Whether you think that struggle is being presented or executed in a satisfactory way is of course an issue of personal taste. I give him credit for aspiring to do more than make just another mindless wank game.
It's not about treating them as sexual objects but as adults. I'm going to compare this to mlc, where the father is still a father and makes clear over and over again that he is going to allow the daughter's to explore whatever they want to explore while not pushing for anything.
He respects his daughters and allows them to explore their sexuality and attraction to him at their pace. He respects their agency, and makes clear that he is first and foremost a father all while being honest with himself that he does have sexual desires with them while holding himself back from pushing or forcing anything.
You never see him doing sleep sex, perving on them without their approval or any objectification of the girls. He acts like a man, and not a, well a cuck. He's honest with himself, he's honest with his daughters and wants to be honest with his wife while attempting to help her explore her sexuality and not repress her desires and cause neurosis. He acts like a father first in everything and a man all while being honest with himself.
MLC is also not a quick fuck, there's a lot of content with teasing and sexual innuendo while being honest about it. MLC's MC scene confessing everything to the escort makes clear he also struggles with the morality of the situation and I'd argue that dev threads that needle far better while being a realistic man with balls.
This MC in single again has gone far far beyond the point at which a psuedofather would have put his foot down and rejected the girls, or accepted their agency and be halfway honest with himself about his own attraction to them.
The constant flashback to finding his wife cucking him just shows his inability to take control of anything of his life, take responsibility and grow a pair.
He's anxious, neurotic, weak, dishonest and just an overall beta bitch. He doesn't actually act as a father would in this situation in any way shape or form, he acts like a born and bred cuck. More than willing to allow sexual opportunities to pass by in favor of having his girls give up on him and find someone else.
Mlc is far and away a far superior story in honesty and masculinity. The mc in single again is an effeminate, weak willed, dishonest, excuse for a man. It's well past time the player is AT LEAST, given the opportunity to put a stop to it or allow himself to honestly feel what he feels. If the player is a cuck or a pubescent male I expect single again will make sense, but any adult male is going to have a hard time swallowing the MC's Inability to exercise his own agency.