I read a similar quote/theme in a lot of the old cowboy Westerns I like- except it's along the lines of people tend to be more polite when everyone is armed- because disputes tend to be settled with guns.(Wasn't there a quote from one Conan story along the lines of, "Barbarians are politer than civilised people, because an insult is more likely to be met with an axe to the head"?)
I always thought "Well, that's one way to keep the population of quarrelsome people under control..."
Either way- it's a rather appropriate saying where Orcs are concerned!