Bourdieu is suggesting that you can't explain the media simply through economic terms, unlike the other areas mentioned. Science, say, can be more explained through economics- no money, no research, while the media merely report what goes on in science, so they are autonomous- they are not dependent on science- as long as there is science, they can cover it, whatever is happening.
While he recognises that economics is important, there are social factors that lie behind the way the media shape their view of events, turning everything into 'anecdote and scandal', reducing everything to the shock and horror of the more excitable areas of the media.
(This is how I interpeted the passge- I am sure that other people might see it differently)
