the whole point is that he eschews classical logic/rational actor stuff to begin with, the operating "logic" is typically "i feel like it" or "i feel like it'll be annoying later if i don't."
"I'm curious how pissed off you'd be, and how strong you are exactly, so here, i'll taunt you and get you to use max power." "I wanna see if you actually can convince me, i read about that talk-no-jutsu bullcrap in typical shounens, so what does that actually feel like?" "I have an idea, i believe, of why you're doing this... but i'll ask because it never hurts to know more."
It's not "go with the flow," it's "set his own flow." Which is why he gives no fucks about training except to get people to stop nagging at him (and then stops as soon as the nagging falls behind his annoyance/pain/fatigue). Which is why he helps out picking the present, because he is interested by aaliyah, because her behavior has written that into his flow.
Condescending assholes go "inexperienced! poorly written!" not understanding that it's meant to be impulsive, inconsistent, and filled with double standards.
He's a high schooler, and especially childish and petulant... and brutal. You're declaring it "bad writing" because you like the funny overblown and harmless chuuni trope, not this logical extreme of that very same.
People IRL use double standards all the fucking time, especially foreign policy and politics, but one sociopath using it in everyday life is enough to set you off? What "poorly written," there's people out there firebombing cities and looting resources under the name of democracy.
edit:
if you want to accuse the author, accuse him of self-reporting some very creepy tendencies/freudian slips, but don't accuse him of making a shit character when all he did was make a character operate off of fundamentally different principles. (have none of you heard of NIMBYs? the classic "got mine, fuck you" attitude? the lolbertarians saying all authority and rules and laws are bad?)
Otherwise a guy could write about a real, living phrenologist (or better yet, a guy who claimed that you needed enslavement to make any valuable art! who also wrote about, similarly, "will to power" and eschewing both classical logic and dialectics!) and yet be accused of "bad writing," at which point the whole idea of "badly written character" is invalidated.
edit 2:
again, think an experienced player in a game doing NG+ shenanigans, clicking shiny buttons they see when they have the energy and otherwise lazing about in their favorite corner otherwise. they fuck around, they don't give a shit insofar as they can keep lazing, if it blows up they're excited to see where it's gonna go but also very nervous cuz they're afraid of losing their acc/save file, they get super on-edge when they think they'll be forced into events instead of being able to take it at their own pace.
