Yes but one thing you have to understand the tv business is different then it was in the early 90's. With the cost of production soaring and audience levels dropping (and ad rates not increasing like cost) networks don't have the financial cushion that they once had. They can't give shows a large amount of time to find an audience.
There are a few exceptions, some shows manage huge critical acclaim (Firefly wasn't one of them,it was liked by critics but was not a critical darling). Or they see signs of growth in important demographic groups.
Without us (and we didn't, it wasn't readily available to the general public during this time) being able to track the demographic detail of the audienceweek to week, we can't judge anything besides raw numbers and frankly those don't tell the full tale.
For examples you can have a show with 10 million viewers make less money then a show that has 5 million viewers on the same network. If Firefly's audience didn't fit the demographic makeup that Fox is seeking for its advertisers then Fox isn't going to pursue that property.
For example both Enterprise and Voyager had typically the oldest average age audience on UPN. THose two shows typically made (per viewer) less then almost any other show on UPN. THus they needed to provide much larger sized audiences to be worth while to UPN.
If Firefly for example was similar then it would need to have a much larger then average sized audience. Of course they could have had a young audience, I don't know (again that data was never made public). Of course then their is the gender breakdown (also important) and then the income. Both of which have importance.
You also then have to look at the whole schedule Fox has. Shows live and die on not only their own fortune but the success (or failures) of the rest of the lineup. You would have to see breakdowns of each of those other shows also.
Without that data no one can rationally make a legitimate argument about whether Fox should have kept Firefly. You simply can't.
You can be upset, and hurt. But you can't judge Fox without seeing the full reason why they made their choices.
To do so is utterly foolish.
Of course now days we do have a lot more access to that information. We can usually see demo breakdown among gender and age. They occasionally release ad rates for each show per minute, we also get some info on income level of audience, audience loyalty, more info on foreign rights, ect. We don't get a full complete picture but we get about 8 times the data we used to see.