First off, I respect anime a lot. I don't watch as much as I'd like to, but Miyazaki and Takahata are two of my favorite filmmakers of all time, animation or otherwise. I'm also a huge fan of Akira, and a smattering of different series here and there. I'm poking fun at a specific group of anime consumers, not all anime consumers, and not the medium as a whole.
Appropriating the imagery and context of one of the most horrific events in human history to provide backstory for an anime/manga with a nationalistic and right-wing subtext in which the Jewish analogs are able to transform into literal monsters is pretty fucked in my eyes.
But you are not discussing AoT japanese right wing undetones, you are discussing "why they using fakejews in my zombie war animu".
Right wing politics have not the same connotations or ideologies in all parts of the world.
The Asians don't have much reference on WW2 other than their own shit which is just ignored 99% of the time.
I'm sure that if the ancient Egyptians were still alive today they'd probably hate the portrayal not to mention the Romans.
What about the Native Americans who got genocide'd so white cisgender folk could start slave businesses on their lands and make movies about their deaths at the hand of Clint Eastwood.
Also you have to admit that the Nazi's made some kick-ass designs. As horrible as they were their Hugo Boss suits (that they froze to death in the fuckers), Panzers, Rockets and experimental planes looked awesome.
Not to mention the crazy names on those things.
There's always going to be someone offended somewhere.