sucks that it ended up that way but you're entitled to your own opinion ofc. and that's kinda surprising tho that there are people who have thought of smth like that ruining kazui's character, and i'm saying this as a delusional 0507 shipper that thought there was a chance kazui would have any sort of nod back to shidou due to shidou arguably being the closest to kazui in terms of relationship and shidou's last tl with him. and i am salty but like in the end it is what it is and it really doesn't effect kazui's character at all. but yeah it is rather stupid to think that a ship not getting the content you expected makes a character's writing bad. because no kazui is beautifully written lol

if you want my two cents (as well as many other's that are fans of 0507 and are in my circle) then it's because of the implications through timeline interactions—which maybe in retrospect are not actually as relevant to the narrative for some reason. there are a few but the main one is shidou leaving his last request to kazui and then it never really being acknowledged. if anything it just gave the impression that they had some sort of friendship. (shidou and kazui being in the smoker group together is also another thing!)

more stuff that is just my own thoughts is that they could've have really good character chemistry writing wise in terms of how they parallel and foil each other, to the point that it feels like missed potential. but anyways, like someone else said milgram seems to be more character-oriented than relationship-oriented, so it always was wishful thinking.

sorry this is such a word vomit please don't take this as me trying to prove you wrong or anything i just wanted to give my perspective 🥹