I suspect one of the reasons, if not the primary reason, none of this is taught is because the instructors don't know it. Brand new CFIs are mostly clueless about this stuff, and unless they know it, they can't teach it. The blind are generally being led by the blind.
Another reason is that it is impossible to teach everything, because no one knows everything. The pilot will be taught what he needs to know for the job, if the company's training department (which may consist of only the owner) is any good at all. One of the largest helicopter segments is offshore support, and you won't find that taught in any school other than the training departments on the Gulf coast of the US, or comparable departments in other countries. It's just not feasible to teach that stuff - how to find a platform a hundred miles offshore, with no navigation equipment other than a compass and a watch. Today there is GPS, but it can fail. I flew offshore in 206s for years with no GPS, no LORAN, just my watch, a mag compass, and a map which didn't help a whole lot. You learn on the job, not in school, and that isn't likely to change.