I think the case about dialect I made in response to OPs question is the better explanation.

You obviously work in a far more open an relaxed sector than I do. I administer in forestry services within Germany. Usually we get foreign subcontractors to do hard labour felling trees (European competition laws are the main culprit). It is important for everyone’s safety that they understand precisely what is at stake. Anyone not using precise language and relying on the information gained trough insufficient means is a moron in that field of work. And thinking, that, understanding a little of what was being said is enough to gather the entire context, a lot of the people we work with rely on that. To combat that we partially switched to pictograms.