I see where you're coming from. I personally had a decently fun time with it, but it has a lot of problems, most of which are endemic to Joss Whedon as a writer and director (the constantly just-a-bit-too-clever dialog, the relationships that always end badly out of nowhere, etc.). Him and his shows get a huge cult following because they cater so openly to nerds otherwise under-served by mainstream television, but neither are as great as the pedestal they've been placed on would lead you to believe.
Also, as someone who has spent the past several years studying the Chinese language, it always annoys the fuck out of me how tacked on the Chinese elements are and how impressed so many people seem to be with them. They are completely inconsequential window dressing displaying no real knowledge or insight.
EDIT: Oh, I also thought I should point out that the number of people who like Firefly is actually much smaller than most people in this thread seem to perceive it to be. Its fan base is an extremely vocal minority which happens to be concentrated in the circles we frequent, creating an illusion of extremely widespread popularity which got Serenity made. I say illusion because Serenity then failed to make back its budget in theaters (going by the world wide gross listed on imdb), showing that the actual fan audience was not nearly as large as had been supposed.