So, why is this an issue? Have control cables become flavour of the month? Is this really an aircraft AD or an AD against sub-standard maintenance?
Maybe because they are just soooo old. Control cables might have been quietly corroding away for half a century, without anyone looking at them much. Hopefully most of those planes are well maintained but when many are so badly neglected on the outside, you can only wonder what they're like on the inside. Maintaining a 50 year old aircraft taking into account all of the ageing issues properly is not going to be a good economic prospect so to keep some of those old s--tboxes flying profitably, one can only wonder if corners have been cut. I'm guessing like SIDs for Cessnas, we're going to see a lot more of this stuff as the fleet ages.