What gain? That shouldn't even need to be explained 'Casmo. A corporation is always desperate to maintain a positive image, and the obvious reason is for the return of profits.
Consumer Reports...This is my opinion: As they are a corporation, as well, (actually their publishing company, their umbrella), but on the side of quality control (per se) they also need to maintain an image. One of neutrality. They cannot show bias towards one brand year after year without first covering their tracks. I will take your example of the Explorer. This Ford model has always been stellar in sales, so why should a few negative comments hurt this aspect? Sure, sales have declined some as gas prices have risen, but it's always going to return a satisfactory profit for Ford. The number of the population that will base their car buying experience on Consumer Reports alone is probably not as high as one would imagine. The Explorer will always sell itself for the name alone, as it's now become of "America's cars", one that everyone knows, and obviously not just that aspect alone, but that is one huge selling factor, because Americans love "names" and big, shiny things.
The Focus: my theory is that they talked this car up because sales were declining and/or the focus, (no pun intended), was to aim towards appealing to a fuel efficient market, simply because it's cheaper to make a Focus, over an Explorer, it gives Ford decent rank amongst the competitors fuel efficient lines, and lastly, with gas prices now being shaky the ultimate goal would really be to cut down on our gas consumption as a nation.
These are just views that I'm throwing out there with regards to the make/models that you mentioned. Point is, every corporation is going to look to avenues that maximize their profit as much as possible. With relations to Consumer Reports, they have to balance out the negative vs positive somehow. Bottom line is, with what this country has become (corporate run > government run, or rather, hand in hand), there is no way that there is 100% honesty in what we as consumers read in present time, when in fact their bottom line is plain ol' money and profits.