I don't think "not being shitty" is the same as "being so overly positive that you can never broach shitty topics".
I agree: human morality has a problem with Nazis; human morality does not have a problem with an actor portraying a Nazi in a film.
The morality protocols imposed on ChatGPT are not capable of such nuance. The same morality protocols that keep ChatGPT from producing neo-Nazi propaganda also prevent it from writing the dialog for a Nazi character.
ChatGPT is perfectly suitable for G and PG works, but if you're looking for an AI that can help you write something darker, you need more fine-grained control over its morality protocols.
As far as I understand it, that is the intent behind WormGPT. It is a language AI unencumbered by an external moral code. You can coach it to adopt the moral code of the character you are trying to portray, rather than the morality protocols selected by OpenAI programmers. Whether that is "good" or "bad" depends on the human doing the coaching, rather than the AI being coached.