And again, the entire point of a Manga with an original LN is to make the readers interested in the source material instead. If the adaptation sucks, then readers won't even bother checking out the LN. To refer to the LN to get the "better experience" is to put the carriage before the horse.
Hell, even if we're supposedly using the the LNs as the source, i can still debunk the teacher's idiotic philosophy, seeing that i have already read through the LN before. Fine then, let us all analyze this so called "uncut" and "better experience" alright? I'll go through each and every statement of their exchange starting from after rebutting Aiko since the beginnings are the same, excluding stuffs that add nothing to the arguments.
"If there was some way back home, I’d take you all with me in a heartbeat. That hasn’t changed even now. But right now, there isn’t one... and if there isn’t, I’d at least like to do what I can for the people I’ve met, talked to, laughed with in this world. Isn’t it only natural to want to help other people?" So this is Aiko's first answer to Hajime's rebuttal. In which she emphasized that she wishes to help those she has met, talked to and laughed with, and it's natural to want to help those people. Okay then, reasonable enough. However, that statement doesn't apply for Hajime. The people that Hajime has "met, talked to, and laughed with" only included Yue and Shia, and maybe some people in Brook Town. There was not a single person currently inside this town that Hajime cared enough about to even want to help them, after all he has only been in this place for less than a day, and most of that was spent sleeping. Mind you, the first impression he had of this area in the LN was a bunch of stuck up knights pointing weapons and him. Even if Aiko's speech is trying to generalize everyone, Hajime still isn't attached to anyone other than Yue and Shia enough to lend his aid. And isn't Aiko contradicting herself a bit here? She wants to do her best to help those she met, talked to and laughed with, meaning that she wants to help those she care about.
"Nagumo-kun, I can understand your strong desire to return home. You probably want to go back more than any of us. But you know, do you plan to live like this when you return too? Ignoring everyone except those close to you? Eliminating anything that gets in your way? Can you really live like that in Japan? And if not, do you really think you can change your mindset the moment you get back?" Yes, that is a perfectly valid way to live. Have we ever seen this teacher actually go out of her way to do anything for strangers back in Japan? No. Even if we consider this mentality alone, it is still within reasonable expectations, in fact, it is the mentality of most people in this world. Tell me, have any one of you here ever done anything when you read the news about war, famine or accidents? Have you ever donated anything to anyone? If you have ever seen a fire happening, have you ever actually thrown yourselves into the mix to try and save someone, or would you just stand there with your smartphones in your hands taking photos of your newest tweet? Unless your direct family or lovers are involved, i doubt any one of you would ever actually lift a finger. And no, dialing 911 when you see a fainted body isn't really much at all compared to what Aiko is asking from Hajime.
"Nagumo-kun, I understand that you have your own principles, and that you’ve already decided your path for the future. I won’t try to change that, but I also think that no matter which future you choose, it’s... too lonely to only live by ignoring everyone aside from those you care about. If you keep going like this, neither you nor the people you cherish will find happiness. If you want to find happiness... you can’t lose sight of your kindness or empathy. You have to think of other people, even if it’s only a little. Those are valuable qualities you possessed from the start... Please don’t throw them away." Do you see the hypocrisy here? Aiko won't try to change Hajime's choice, she is just implying that one of his choice is lonely, and would lead to unhappiness. That is not the freedom of choice, that is an ultimatum, and at most, sophism. By invalidating one of his choice, she is literally forcing him to do what she wants. And as i have already explained before, living while caring about only your friends and relatives/lovers is a perfectly valid lifestyle that most people have. No one has the mental capacity, the ability or even the reason to care about strangers around the world. Tell me, would you say that a father who tries his best to make a living for his wife and children while not implicating his friends is selfish? Would you say that an office worker is less honorable and more "lonely" than a police officer (disregarding the fact that the police do get paid)? If you say yes to any of these questions, i would suggest you get off your high horse and look at what you've managed to do to the ones close to you.
"So, even if he couldn’t sympathize with others right away, he could still act. And if those actions brought happiness to those he cared most about... to Yue and Shea, then he’d gladly do anything." This entire logic falls apart when we realize that even Yue and Shia only care about Hajime and their close friends, not anyone else. Did you remember what Yue and Hajime said before leaving the 1st Dungeon? That they would move forward by themselves even if the world tries to stop them. This is their resolve and their mentalities. They're both fine with anything as long as the other one is happy and make his/her own choice. Aiko's plead would have actually had more ground had any one of those three actually gave a dime about anyone else other than the other duo. And last time i checked, Yue and Hajime had no problem abandoning Shia to the Monsters either.
"I knew I’d get found out eventually. It was just a matter of time. I already have a few countermeasures in place, and besides, I promised myself I wouldn’t hide who I am just for the convenience of the people in this world... Hell, it might be fun to cut loose and go all out every now and then." Not even once in this entire inner monologue did Hajime even agree with his teacher. The only thing he did was try and justify his foolish choice, making excuses so that he doesn't feel conflicted.
"If he did decide to help, it was possible things would come to a head with the Holy Church much sooner than he would have liked, but surely he could count on his teacher, Aiko, to help with that. After all, she had to take responsibility for what she’d said to him. And someone who loved her students this much wouldn’t refuse." For someone like Hajime to place his trust on anyone other than Yue and Shia at this point is a mis-characterisation. To begin with, what could Aiko possibly even do with her tiny power? Nothing much i would assume. From the very beginning, when Hajime and Yue were still only by themselves, they already had the resolve to face God even if it was just the two of them. Under what circumstances would Hajime even benefit from placing his trust on Aiko, who is much weaker and more naive than him? Tell me, instead of placing his unguided trust on his teacher to resolve the aftermath, wouldn't it be much better to just avoid creating the situation to begin with? Please try and view things from the perspective of someone like Hajime, not from an omniscience POV, because that's not how logical thinking works. Hajime had no reason to even believe in Aiko to begin with. He wasn't there to see Aiko's expeditions, he doesn't have the ability to read people's minds so he can't possibly ascertain that Aiko is capable or trustworthy, and he has only spent less than one day with her, nowhere near enough to let him have faith in her. This is even worse when he decided to tell "Ai-chan" everything, since he had even less time to judge her character at that point. This is why i tell you to see things from the character's perspective, not your godly pov who knows everything about every characters. I know about the future anti-church incidence, but the characters themselves do not know that, so don't even try to use that as an argument.
And you know what's the most hypocritical part here? Aiko did nothing in the entire fight. She just sat there, behind the fortress, being protected by Hajime and company. Those sure were some big words being thrown around by someone who hasn't contributed a single thing in the process, while letting others do the job for you.