They had to be receiving kickbacks of some sort(be they monetary or sexual).
The game isn't complete rubbish, but the shining reviews granted the title by journalists are unfairly positive. Sure, the open-ended approach is a welcome change to the FPS genre, but the details of Ubisoft's implementation of that approach are too glaringly bad to be taken for granted.
Being able to approach an objective from any angle loses its value when the enemies you are sneaking up on can see the pimples on your ass through jungle underbrush in the middle of the night from 100 meters away without so much as a toy telescope(these AI shennanigans were one of my main issues with the original Far Cry). The same can also be said of their fallen bretheren. Since when can a guy 50 feet away from your target (and 100 from you), looking the other direction, instantly tell his comrade has been shot with an AIR RIFLE and immediately start firing on the attacker.
Frankly, the superhuman AI alone is enough to entirely negate any potential benefit from the open-ended mechanic. It leaves the player with pretty much one option for successfully completing a mission - brute force. You can't pick off scouts from afar and then make your way in to clean up the rest without half a dozen goons running right for your position, and you sure as hell can't quietly sneak in to the base and wait in a corner for your target to approach (these African supersoldiers can see through walls, you know).
There's more, but this thing is already starting to turn into a Tolstoy volume at an incredible rate