Well if thats worrying then it may worry you to know that the worlds biggest international airline also has the same rule...only those adjacent to the exit row need to be open!!!!!
And do you know why???? So the crew can see what they are doing because afterall they are the only ones who have undergone the training! If that crew member was incapacitated I seriously doubt a normal passenger whos only care at that time is their own survival (priority one being to get out of the wreck regardless) would even think of looking outside for hazards because as far as they are concerned, being inside the plane is the biggest hazard!