How sci-fi can have drama without dystopia or doomerism

Whenever this comes up, I note: I think this is only a problem for a certain kind of nerd/geek who wants particularly intense stakes.

Sitcoms, soap operas have plenty of interesting stories that are mostly about low-stakes interpersonal drama. 

(I guess this cached annoyance of mine is more about people complaining about utopian fiction rather than science fiction. But I think the same principles apply)

I'm confused.  You start with

“But you can’t have a story where everyone is happy and everything is perfect! Stories need conflict!”

And then list a bunch of conflicts.  David Mamet's three rules are:

1. Who wants what from whom
2. What happens if they don’t get it
3. Why now

And all of your examples are fair places to answer these.  I think we don't actually disagree, but I'm not sure I understand the objection you're responding to.  Did someone actually say "there's no tension without dystopia"?  If they only said "dystopia is the lazy person's generator of fictional tension", then I kind of agree.

Stanley Kubrick is perhaps one of the most influential Sci-Fi filmmakers of the 20th century, therefore I believe he has some authority on this matter. What may answer the need for dystopia can be extend to war and crime films:
 

...one of the attractions of a war or crime story is that it provides an almost unique opportunity to contrast an individual of our contemporary society with a solid framework of accepted value, which the audience becomes fully aware of, and which can be used as a counterpoint to a human, individual, emotional situation. Further, war acts as a kind of hothouse for forced, quick breeding of attitudes and feelings. Attitudes crystallize and come out into the open. Conflict is natural, when it would in a less critical situation have to be introduced almost as a contrivance, and would thus appear forced, or - even worse - false. Eisenstein, in his theoretical writings about dramatic structure, was often guilty of oversimplification. The black and white contrasts of Alexander Nevsky do not fit all drama. But war does permit this basic kind of contrast - and spectacle. And within these contrasts you can begin to apply some of the possibilities of film - of the sort explored by Eisenstein."
https://www.archiviokubrick.it/english/words/interviews/1959independence.html 

More specifically he explains the way he believes Speculative Fictional genres, such as fantasy and Sci-Fi can be effective towards expressing certain ideas which realist drama - the kinds you're advocating albeit within a Sci-Fi environment - may not be. Interviews taken from these transcripts: http://visual-memory.co.uk/amk/doc/interview.html 

Michel Ciment: You are a person who uses his rationality, who enjoys understanding things, but in2001: A Space Odyssey and The Shining you demonstrate the limits of intellectual knowledge. Is this an acknowledgement of what William James called the unexplained residues of human experience?

Stanley Kubrick: Obviously, science-fiction and the supernatural bring you very quickly to the limits of knowledge and rational explanation. But from a dramatic point of view, you must ask yourself: 'If all of this were unquestionably true, how would it really happen?' You can't go much further than that. I like the regions of fantasy where reason is used primarily to undermine incredulity. Reason can take you to the border of these areas, but from there on you can be guided only by your imagination. I think we strain at the limits of reason and enjoy the temporary sense of freedom which we gain by such exercises of our imagination.

Michel Ciment: Don't you think that today it is in this sort of popular literature that you find strong archetypes, symbolic images which have vanished somehow from the more highbrow literary works?

Stanley Kubrick: Yes, I do, and I think that it's part of their often phenomenal success. There is no doubt that a good story has always mattered, and the great novelists have generally built their work around strong plots. But I've never been able to decide whether the plot is just a way of keeping people's attention while you do everything else, or whether the plot is really more important than anything else, perhaps communicating with us on an unconscious level which affects us in the way that myths once did. I think, in some ways, the conventions of realistic fiction and drama may impose serious limitations on a story. For one thing, if you play by the rules and respect the preparation and pace required to establish realism, it takes a lot longer to make a point than it does, say, in fantasy. At the same time, it is possible that this very work that contributes to a story's realism may weaken its grip on the unconscious. Realism is probably the best way to dramatize argument and ideas. Fantasy may deal best with themes which lie primarily in the unconscious. I think the unconscious appeal of a ghost story, for instance, lies in its promise of immortality. If you can be frightened by a ghost story, then you must accept the possibility that supernatural beings exist. If they do, then there is more than just oblivion waiting beyond the grave. 

And to finish, I can't the source at the moment (I think it was in "A Life in Pictures"), but it is like Jack Nicholson said of Kubrick "then someone like Stanley comes along and asks: it's realistic, but is it interesting?".

A dystopia provides a background, a framework that allows a highly catalytic environment for dramatizing ideas that cannot be done by means of regular small stakes interpersonal conflict. Even Plato knew this with regards to pedagogy: hence why his Socrates suggested like the way you use big handwriting to make a manuscript more visible, he expanded the vision of justice in one single person to the entire polis.