On 'reality' tv: It's incredibly cheap to make compared to a show with a 'star' or 'stars'. If the audience accepts such programming, even clamoring for it, then I cannot fault the business logic in pushing them out like Owebama pushes out lies.
As for Firefly, the cult following pushed to have Serenity made, so they did their job. And in a lot shorter time frame than the Trekkies.
The thing I like about Firefly is the sci-fi part of it. It's gritty, dusty, muddy, rough and tumble. Plus, they carry revolvers as part of their arsenal. Unlike Star Trek, which is pristine clean, no money grubbing (no money! ah, but latinum . . .), minimalist society that happens to have warp drive and can make some really cool and big weapons. The Federation is just too Utopian, too against human nature for me. Firefly, on the other hand, embraces that individuality and rolls around with it in the muck it so amiably portrays. I also thought the Chinese angle in Firefly was pretty prescient.
There are times when a work goes staright to video. After Serenity, this show would have been a good candidate. As long as the production values and story lines were maintained, they could have created their own Babylon 5 empire. But the problem for actors in such a show is that usually they are unknown and are itching to become known, so they don't stick around, hindsight being 20/20. Maybe if Whedon had brought in Straczynski . . .