That point yes, but not your point overall. Fox has also brought back internet-popular cancelled shows like Family Guy and Futurama (for years, the three Fs seemed to be the main beef people had with the network).
We can't really count Family Guy as SF (yeah they did the Star Wars thing and the occasional fantasy episode ... but so did the Simpsons and it's not considered SF). Futurama? Yes, I'll concede that. However what about Wonderfalls, Terminator, etc.? Futurama isn't the only show that was Internet-popular. It (along with Family Guy) were crumbs - not to mention far-less-expensive crumbs than, say, bringing back Firefly.
The problem with this geek narrative is it assumes a level of wilful neligence that doesn't make a lot of sense. If Firefly was destined to be a monster hit, don't you think Fox would want that to happen and then milk the damn thing dry until Mal Reynolds plush dolls were lolling around spouting pseudo-badass nonsense in every house in America?
Then why did they air it? They SHOULD have done exactly what you said, if they had the confidence in the show. They certainly did with X-Files. (Just a point of disclosure - I hate Firefly with a passion, so I'm not Browncoating here. But I certainly understand with and sympathize with those who felt it was unfairly treated by Fox).
The series didn't do well in the ratings so it got cancelled. It did very well on DVD, and the response from TPTB was fairly immediate: Go and make a movie. The movie didn't do well enough to justify sequels, though.
Making a movie at this early stage was a huge mistake. The cost of the movie could have gone towards producing a mini-series, or a second season for another network (remember TPTB did not include Fox). It was way premature to do a movie, so it surprised no one when the film didn't do as well. I heard a lot of "WTF is Serenity"-style comments when it came out. It was huge in the SF niche fandom, but it hadn't had a chance to go mainstream yet. By comparison, had Futurama gone to film instead of being brought back it probably would have done OK.
Which is to say, Fox didn't maliciously pull the plug. They may have screwed up but in theory they would have wanted the show to be a success. Everywhere Whedon fans were howling that Dollhouse could never survive a single season on Fox, and it seems surviving two and then kicking the bucket is a 'same-difference' appeal for them (but then, if the show isn't too popular, what else should Fox do?)
Well, getting it off Friday and into another time slot for a start. There seems to be this mindset (and not just at Fox, to be fair) that most shows live or die depending on how the dice rolls for their timeslot, and a show is rarely moved away from the hand it has been given. Dollhouse (and Terminator) tanked on Fridays. Who is to say putting DH after Fringe or on Sunday night might not have paid dividends? We don't know because they didn't try.
Also, especially with a show like Dollhouse, Fox and its advertisers need to once again realize that this is 2009 and that the viewership of any show cannot be accurately gauged anymore just based upon the Neilsen ratings for a broadcast. It hasn't been the case for years. Yes, some sort of gauge is needed to make sure sufficient viewers are looking at a production. But with DVDs, downloads (illegal and legal), etc. there's more to take into consideration.
Sucks to be an advertiser, for certain. But the advertising industry has always rolled with the punches, so they'll come up with a workaround, such as more sponsorship of sites like YouTube, Hulu and Fox.com, or maybe there might be a bit more product placement in a show, which I really don't understand why people get worked up over as long as it doesn't interfere with the story. With was only about 40 years ago that scripted series like Bewitched stopped incorporating company logos into their opening credits. (Check this out:
http://www.youtube.com/watch?v=JnDF3-Forms)
Is Fox being malicious? No, of course not. There HAVE been strong allegations of "malicious cancellations" made against shows like the original Doctor Who, Enterprise and most recently Southland. But I wouldn't call the cancellation of DH (or Firefly for that matter) malicious.
I do, however, think the decisions are being made based upon outdated business models and need to be brought into the 21st century before the mainstream networks cease to be viable as more viewers and producers turn to alternate media. We've already seen Whedon test those waters with Dr. Horrible and it's generated more mainstream response than anything he's done since Buffy and Angel.
Alex