Earlier quoted context omitted.
It’s the same story as the Casio F-91W as well as the AK-47. Terrorists (or just any armed paramilitary group) who live in the back country far from common supply lines have a great need for standardized, rugged, reliable, and repairable technology. By living that life, they’re basically forced to think about these issues as a matter of survival.
Well I think the F-91 is durable, it’s probably not repaired as much as discarded as it is cheap. Disposable is likely the advantage there.
The fact that the watch is so ubiquitous means the paramilitaries can write and distribute a standard field manual explaining how to do this, knowing that anyone wanting to build an IED ought to be able to acquire some of the watches on their own.