"Responsible" is a highly overloaded word, but if nothing else it's a call for writers to be cautious in how they present things.
I'm working on a story with a (mostly) sympathetic protagonist who does some awful things and ultimately undergoes moral meltdown. One of my beta readers pointed out that my ending, bleak as it was, sort of rewarded the protagonist by giving her catharsis and some vindication, if not an actual happy ending. I took that as the top priority from that round of feedback and made sure to tweak the framing.
Did I succeed? Maybe. Can I absolutely prevent people from taking the wrong message? No. But I can try, and at least cut off the obvious routes to misinterpretation, learning from previous examples (Fight Club is actually not too far off in spirit). I think this is a moral responsibility of anyone making art, especially stories, for consumption by others: you at least have to try, where "try" includes a good faith effort to learn from common mistakes.
I don’t think the author is the relevant person here. The filmmakers are, and they pretty clearly chose to make Durden a charismatic figure and Jack an awkward one. And of course they would - it makes for a better story and overall film.
Beyond that, I think most films/shows are functionally the same. No one wants to watch an ugly, uncharismatic actor just…fail. That doesn’t make for a good story. It seems pretty obvious to me that the vast majority shows are produced based on the quality of the story, not on instilling ethical values. Otherwise why would something like Dexter even exist?
Durden is, according the author at least, an imaginary character. In his mind at least that overrides the "charisma" level. So make of that what you will.
People preferences for story telling is partly why the really good story tellers are so reverred: they make us comfortable, engaged even, in stories in which our natural inclinations would lead us towards different outcomes. We don't like watching ugly, uncharismatic actors fail, but the good stories keep us engaged when the pretty, charismatic actors get their just rewards for bad behavior.
I have no idea why anyone would think that Dexter is not a tale about moral values, and the "right ones" too ...
Should an author be responsible when they create a what they intend to be a cautionary tale only to find that it is interpreted as a celebratory tale?