I prefer having a blank canvas where my decisions form the character and perception of the main character.
People are different, this is not a bad thing. However, since you've decided to be a part of this discussion, rather than leaving a review, I have to assume your purpose is in an attempt to get people to come to your point of view.
I love the Elder Scrolls and Fallout games, not 4 as much, but overall, I love them. Why? Because as you say, it is nice to have a blank canvas that is meant to be a role I play. I also play tabletop games, as the game itself should have put up flags for, and what is a tabletop RPG if not an excuse to create a self insert character who does the things you want?
However, at the same time, I love The Witcher series, in which you play as the very defined protagonist Geralt of Rivia. Geralt is not a blank canvas for you to self insert onto. He's very much a more traditional masculine character. Similarly, I quite like the Mass Effect series, however, Shepard, no matter if you play them as Male or Female, Biotic, Engineer, or Soldier, comes off as a typical soldier type. Even though you get to create and mold the look of the character and their abilities to your desires, the character is by no means a self insert.
When it comes to adult games, the majority of my favorites are characters with defined personalities, The Deluca Family, Wicked Choices, Coceter Chronicles, Depraved Awakening. All these games give me choices, but the characters themselves are pretty well defined as is. I've found, what these stories have that self insert stories do not, is actual depth to the characters and stories. Personally, I don't play games for the art, while I think it's an important part of making a good game that your art be good, I have no particular liking for Daz, or for Honey Select. If all I wanted was to see characters fucking, I'd go to pornhub.
No, what I look for in a game, and hope to provide myself, is an emotional experience that leads to a more satisfying release when the sex is involved. One thing a relationship requires is give and take, from both parties. She has to have something she needs from you, you have to have something you need from her, and over the course of a relationship, those needs being met, you get a stronger sense of fulfillment. To drop the flowery language, in my opinion, the orgasms are better. Here's the thing though, that's impossible with a blank canvas.
You can design the love interests to need something all you want, but if your MC has nothing but a dick and a high libido, they're not getting anything from any relationship that they couldn't get from any other hole. What's more, because the MC isn't getting anything from them, but is giving something to them, every single blank canvas relationship in games ends up feeling like a one way "gold digging" relationship. The love interest ends up coming off as a superficial, selfish cunt.
When I decided to start writing games, it was to change the narrative, start bringing in these stories of actual relationships that matter. Sure, this one is dark, but it's dark because the darkness provides a canvas on which incest can easily be painted. Yes, I made the victim the male to challenge the societal norms. Yes, that might make you uncomfortable. No, that's not a bad thing. In fact, while I'm not saying you would be this person, if you would have been ok with the game if the roles were reversed, you need to re-examine yourself, your biases, and otherwise.
That's a really idealistic view, but from my experience, reality differs from that perception.
There's nothing idealistic about this. Scientifically, gender is bi-modal. That means that there is a spectrum between masculine and feminine and people lie somewhere on that spectrum. Alex is certainly near the middle. He's not strong and assertive. But at the same time, he would put himself in between an attacker and his sister, and he'd be satisfied in taking a beating, or even worse, if that meant she got away. If that's not masculine, I don't know what is.
You need to remember, your experience is not everyone's experience. You seem to acknowledge people are different. But you're not yet ready to drop the preconceived biases you have been trained to accept by a society that, even if you don't subscribe to it, is largely built on an Abrahamic religious hegemony. If you study other cultures, you'll find plenty of examples of differing expressions of gender, sexuality and otherwise long before Europeans conquered the world. Native Americans had their Two-Spirits, Indians have a legally recognized 3rd gender, and while it's less commonly expressed these days, after British Colonialism stamped down on it, it does still exist. Japanese culture is constantly fighting against our version of sexual morality from their cultural norms.
In closing, it's fine if this game isn't meant for you. But always keep in mind, your experience is not everyone's experience, and having a different experience does not make it wrong, unhealthy, or worse "degenerate".