Um no, he's actually written incredibly well just not in the manner that your incel ass wants. Namely him being written as a psychopathic terrorist vs. some gray zone vigilante.
The things known about him leading into v2:
him smirking as he dismissed killing a train full of INNOCENT people; which likely included faunus which puts him as a psychopathic terrorist
he had a close relationship with Blake that was broken by said train incident
That's it, that's all of his character up to v2. None of which was altered and instead was built on in v3+.
"idealistic faunus man tortured by the Schnees" as not only was it never posited that he was idealistic at all; but the "tortured by the Schnees" wasn't even a confirmed thing till v6 (SIX).
proof that he cares about his people or fighting for them at all, instead he's once again shown not giving a single shit about INNOCENT lives on the train that likely include faunus. He USED the faunus cause to excuse his own psychopathic bloodlust.
I shudder at what your incel ass considers a "trivial matter", cause I'd wager it/they isn't/aren't one/s. Like killing a train full of innocents isn't a "trivial matter".
Actually no, nothing was thrown away. He's revealed as what he always was: a manipulative, abusive, own-ego-boosting focused, power-hungry, and co-opting psychopathic terrorist piece of shit. He goes after Blake because how dare anyone undermine his power, undermine his authority, and risk damaging his ego. Which is furthered in v5-6 where his collapse is shown happening as he steadily starts losing status. Things which match irl abuse survivors stories of their own abusers.
I don't give a single fuck what bullshit ass violin your sorry incel ass wants to try to play for him, he was a psychopathic, abusive, co-opting terrorist who got what he earned via his acts. The writers didn't fuck a damn thing up, they just didn't write him the way your dipshit ass wanted; which wouldn't be THEIR story it'd be yours. They aren't writing your damn story, they're writing theirs.
This whole "confrontation with Weiss" bullshit is just that its naive/ ignorant ass shit. What happens is you end up with the daughter & heir of the racist family auto-winning said confrontation, because the alternative is killing off a goddamn main character. Which isn't exactly a great damn image to portray, especially for a fucking psychopathic abusive terrorist. Instead his story and the WF story were split into separate things as it should be, where his goes towards Blake and then Yang. His victims and survivors that are the ones to take his sorry fucking ass down.
So no not a damn thing was altered or changed; because your dumbass fanon/headcanons are NOT canon. Your wants not being a thing do NOT translate to being bad writing. And your dumbfuck ass wanting to play the worlds smallest most out of tune violin for an abusive psychopathic terrorist who has no care about killing a train full of INNOCENT people doesn't change him being those things thus deserving his fucking fate. Karma is a fucking bitch.