This just sounds like a long-winded way of saying "some people read stories wrong".
Then they shouldn't read the story wrong.
Being serious though, you can read any way you want. But if you try to discuss the story and want to persuade other readers, the first method is not the way to go because you're not using the actual manga at hand to make your points. How can someone else respond without a common talking point?
Is that why we are here? To convince others they are wrong? Are comments like "Fuuko is so dope" and "damn I love me some good drama" somehow more persuasive arguments on the other end of this scale that you put readers on?
In fact, when people here argue that the characters feel like realistic teenagers in support of them and the story, they are then also judging from an outside perspective relating to their own experiences as/with teenagers in their life. When others complain that Fuuko feels like a manic pixie dream girl in relation to the other characters, they are then using the internal logic and "ethos" as was said to compare and base that opinion on. Seems to me some of you are trying to forcefully pigeonhole people in an effort to undermine their opinions.
At the end of the day some will like the manga, some will dislike the manga, we all have our reasons and, indeed, backgrounds to feel how we feel no matter how hard we try to separate real world from NTR fantasy land. And that is where we personally speaking seem to be with this story so far; a fairly bog standard trio of characters with the usual setup, just Nanase and Fuuko happen to be women too which does not really make the story that much more interesting. If Nanase was, say, a diligent guy in the student council wanting to keep his image pristine or whatever, while Fuuko was a freespirited playboy with his blonde hair about to expand some horizons for the MC (with a side of blackmail even), it would amount to basically the same thing. Forced? Sure, but then people are here arguing that Nanase's actual reasonings are not that much better.
Now it is of course possible that this story will make some kind of twist or turn and end up somewhere completely different, or at least get there in a different way I suppose. But until then we can only work with what we know, and what we know is just kind of... eh? And if you think this story is super interesting and engaging then all the power to you, have a great time, I can't agree but that's just the way it goes.