I concur that this is applicable to all hands and that it leads into hand range analysis, range analysis, ABCD theorem, ISF theorem etc etc.

The reasons I chose to focus on 'nut' hands are three:
1) Your opponents are much more likely to remember lines you take with nut hands - especially if your line ends up costing them a big stack of chips. Thus you could argue that it has a bigger effect on your image than smaller hands you play. For instance, I take notes on people playing the nuts weakly and not extracting any value also.
2) I think describing the way the threat of you having a nut hand gives you fold equity will help people understand fold equity and in turn ABCD theorem.
3) It is very common for beginners to horribly misplay nut hands. By this I mean that they (we) slowplay and try to maximise value on THIS hand making it in turn incredibly easy to spot when they are bluffing (cbets count) - since you never play a nut hand fast - when you play a hand fast you cannot have a nut hand and I can call you down or bluff you off your mediocre holding.