I'd forgotten about writing this. It resurfaced in a file recently and I decided to polish it up a bit. I wrote it during the early days of the OWS protests because I wanted to find a way to discuss capitalism in a fun geeky way. Enjoy.
The driving difference between my two favorite future universes is the ways power is made available to their characters. Firefly is a universe in which capitalist systems of distribution and power are still very much in effect. It is a gritty universe and we feel good watching it and fighting for the underdogs who are trying to escape the boot heal of the Alliance. In the Firefly universe there is a premise accepted by all the main characters as well as the audience that you have to be a little but of a renegade or obedient to the current authorities to survive. Under a capitalist system somebody always has to be oppressed, someone always has to lose. This contributes to the drama and connection we feel with the characters of Firefly. We sympathize with their struggle for survival.
In the Firefly universe you more often usually have dramatic life-and-death dilemmas that are intellectually engaging; survival comes first and philosophy coming importantly second. The struggle to survive comes first in the firefly universe. In the opening sequence it is repeatedly presented, through a back story voice-over (& as a recurring theme), that the crew of Serenity is always looking for some kind of work. In the Star trek universe the complete opposite is true of the main characters.
In the Star Trek(TNG) universe more often than not the drama comes from deeply intellectual and often existential questions or thoughtful riddles about morality and ethics. The potential for mortal danger is occasionally present but is less often the focus of the action and discussion. The time and space to think and philosophize is the setting for the majority of the plot lines in the Star trek universe. People are fighting others and themselves to be ethical, not to survive. Fighting for survival is a novel plot device. It is sometimes employed in Star trek but certainly not in every episode. It is most often used to heighten the drama of a two parter or a season finale. Mortal danger in the Star Trek universe is something so foreign that when it occurs it is much discussed and very clearly upsetting to the entire crew. This runs in stark contrast to the ever present mortal danger under which the characters of Firefly live their everyday lives (they joke about almost dying/barely surviving with great frequency).
Of course there are a few other major features that distinguish Star Trek and Firefly universes from each other. Jean-Luc (others too) often recites (without much provocation) the fact that humans in the 24th century are without poverty and even without the need of a monetary system of exchange. There are also higher intelligences or more advanced beings featured as a sort of deus ex machina in the back story of the Star Trek universe. I find myself inferring, from this back story, in addition to the utopian distribution and availability of resources (replicators) that having contact with more advanced beings (like Vulcans) assisted humans in the abolishing of capitalist systems. In the Firefly universe there is no evidence that any organized race other than humans exists. This contributes to both the feeling of aloneness the crew feels as a theme but also the aloneness one feels when struggling to survive. Mal touts at one point: "you make your own luck". This loneliness makes for some really great dramatic storytelling and also lends to the shows larger commercial appeal (more explosions more people getting shot).
The same reason some people might find Star trek boring are the same reasons others might find Firefly too overblown. My love of both of these shows is painful when I think about it critically. Part of me thinks "yeah the Firefly universe is totally an awesome future.” but people (people we love!) die with horrifying frequency & the government doles out large scale oppression over peoples bodies, movements and actions. They employ mercenaries to take out threats to their infrastructure. When I think about the Star Trek universe as a possible future. I find myself heartbrokenly skeptical. Whenever Jean-Luc says "we abolished poverty" the realist in my gut tells me that no, we aren't coming to that, too many humans are still too vehemently and proudly like the hyper-capitalist ferengi. Even those of us who see and feel poverty and hunger and abuses of power are still stupidly hungry for our own pieces of the pie. Honestly, I don't think that, even if there were a Vulcan god machine to descend upon us with a superior and awesome code of ethics, we would be able to relinquish that survival state without our own choosing.
I has been pointed out before that that technology of the replicators presents a solution to the scarcity that causes the fear that drives folks into a survival state. And yes the replicators make the essentials as abundant as needed (and easily distributed). But I'm not convinced that any technology will contribute greatly to the equal distribution of resources. It's failed to happen thus far even though productivity has soared exponentially in the last 40 years.
Think about the distribution of information and the way that is metered by the availability of access to modern technology. Even if they make it simpler to do so, shiny new devices in and of themselves, will not, and have not compelled us to behave in a more equatable manner. This is evident in the Firefly universe where the unequal distribution of resources is very apparent. It's even one of the driving forces of the action. Think about the fancy accommodations on Ariel in comparison to the way colonists are treated or the "rustic" accommodations on Serenity. There is a well developed separation between the classes in the Firefly universe, despite the existence advanced technologies. Some places are “flush" with it "other not so much."
The Firefly universe is great for escapism but you wouldn't want to live there. You wouldn't feel safe in that society. You might die, or most likely get shot once every year or two. The Star Trek universe on the other hand, while it's conventionally less exciting, would be comfortable and safe. As a human you'd rarely ever have to fight to survive (unless it is the season finale and you are a captain or first officer). Now I know staunch capitalists & free-market junkies would love to tell me that it'd be lazy or against that natural Darwinist way of things to want this. But even though the struggles represented on Firefly are pretty shiny, I would infinitely prefer living in the non-capitalist less survival-driven future of Star Trek TNG. Cause I really prefer not being shot. How bout you?