So, people are complaining the clothing looked like, well, real clothing, and the guns looked like well, real guns?
Not really, just that "Space Western" is rather tired and cliche, and I think it turned people off of Firefly before they could see the deeper themes and amazing dialogue/banter/humor it also contained.
I think what I'm really getting at is the superficial "Space Western" post-Civil War, the Frontier, Scalping Indians/Reavers (Taken all together it was pretty blatant, not just the clothing and retro looking guns...) now works great for Firefly that it's got cult status. I just believed it worked against it during it's initial run.
I think what they did with Battlestar Galactica worked better, where it was kind of a suits, ties, and "Vancouver In Space" for the set of planet Caprica. That sort of reflected a subtle truth about the "future". (or an advanced technical civilization, if hundreds of thousands of years in the past..)
If you took people's common perceptions of what "2010" would look like even as late as the 1970's, even 1980's, they STILL would thought "space pajamas" and flying cars, or even when they tried to ground it in some reality like other visions like Blade Runner (2019), or Back to the Future II (2025). The truth is if you could transport them here now, they'd be impressed with our PC's, flat-screen TV's, the Internet, and our cellphones, the cars are a bit more streamlined and rounded, but everything else is still pretty darn the same.
With Firefly, perhaps going with a deliberate retro late 1800's look is integral to the story, but I'll stand by saying that aside from what Fox execs did to the show, I think it interfered with it getting wide acceptance in it's first run.