[ethbr1]

Firefly is "Western" in the same way that 1960s spaghetti westerns (and arguably even John Ford's) were.

Which is to say they used a facsimile of a lawless frontier to tell stories about ideologically stark, independent characters.

Less cactus, more open carry.

[bityard]

I'll grant that Firefly's sci-fi western motif was novel, but it could have done fine without it. The show's magic for me was its characters and clever dialogue. It it was funny, and it had heart. There was an enormous amount of satisfying character development for such a short run.

The Expanse is fairly good on its own and I did enjoy it but it could have totally filled the void left by Firefly if they would have just had a few comedy writers on the team. Instead, we got a ship full of gloomy self-loathing heroes with poor mental health who were too caught up in second-guessing everything they did to fully appreciate the absurdity of everything happening around them. (I know, I know, the show came from a book series, just humor me...)

[ethbr1]

Devil's advocate: deft use of zeitgeist-known settings in time-limited media can make for more efficient storytelling.

A captain of a ship.

An outlaw.

In a western-seeming system of planets.

If nothing else was said, that already paints a pretty vivid background from the audience's preconceptions. All of that exposition can be skipped. Or at most, quickly nodded to in order to confirm.

Sure, a show could rebuild the same thing neater from primitives, but how much show time would that take? Western was "close enough" to the point, so they went with it.