I live in a very direct culture, but that does not mean we’re being impolite towards each other. I work with a lot of immigrants from cultures which do not separate these two concepts, however, and when you tell them to be more direct, or if they are not getting anywhere by merely hinting at what they need, they quickly switch to:

• frowning
• shouting, or talking very loud
• using very short sentences, as if they were ordering people around
• being borderline insulting

And that is not acceptable in any society. I was absolutely miffed by this many times until I understood that they don’t actually know communication which is both direct AND polite because they didn’t grow up with it.
I put together a quick illustration to show what I mean:

So, the people I’m talking about go from top left to bottom right, maybe brushing on bottom left, because that’s the only direction they know.