If profit was the only motivating factor in journalism, then all the other news networks would imitate Fox News.
In this case it is directly tied to tradition. It's a case of "it's been this way so long it can't be any other way". They exist as a profit-making entity, but their traditions have become so blinding even that they are instutionally unable change with the business times. In their eyes, and in the entrenched traditions of their network, anyone who disagrees with them must be nutty. Therefor, this conservative movement thing must be a passing fancy and it will all go back to normal soon.
This kind of institutional tradition is hard to shake, even in the face of overwhelming evidence to the contrary. It takes an enormous shakeup for them to stop, take stock, and figure out "hey, maybe we should rethink this". The old-guard news agencies are finally getting the drift, but only after a couple years of falling viewership and circulation have forced it upon them.
Fox News has the luxury of being a relative newcomer, and being founded by a businessman rather than a "journalist". As an institution they have enough of a buisness mindset to know which side their bread is buttered on. They are capitalizing on the fact that most of the country was/is completely fed up with the way their news was being slanted. They also know (or at least give the appearance of trying) that people will go do their own fact-checking via the interwebz. CNN, MSNBC, and a the major lib newspapers still haven't figured out that this internet thing allows folks to see what really happened, not just the newsies particular views on it.
Brad