Earlier quoted context omitted.
"troubleshooting really can't be taught" Exactly: it is a gift. You have "the Knack". (Dilbert - The Knack "The Curse of the Engineer")
I think it has to do with interests. Some people have an inmate interest in how stuff works, and specifically how it breaks. I think you can teach someone to troubleshoot in a procedural and methodical manner, but they will always lack the creative "spark" that comes from being actually interested. Procedural troubleshooters are useful, but they won't exceed the bounds of the model they've been taught to work under.
Also, for example, so many developers could see an issue and fix it without really understanding how the fix works.
I literally cannot live with that and have to understand why something works the way it works