I agree, Jon, that is is a really useful skill for a teacher to be able to show the relevance of what they are teaching and to relate what is being taught to something the student is familiar with. Without it, you risk teaching repetition of meaningless sentences and magic. Maths is very prone to this; talking to people you often find they know that "you do this" but have no understanding of why. Teaching the why of things - whether science, maths, history or art - seems to me at the heart of good teaching since that is the base for understanding rather than fact-collecting. It just doesn't seem obvious to me that time out in another industry necessarily helps.