I have met a number of Muslim immigrant medical doctors and native born Muslim business men here in Iowa who were very polite. Over generalization like this actually only discredits the accuser. I think that it is only common sense that we should not have diversity visa programs.
These are not normal times. We are at war with a subset of a political movement wrapped in a religious/ethnic shroud. If we don't defeat that subset, we lose the war. Many "innocents" who might not be part of the subset will be killed as collateral damage.
Ask yourself, are those who do not turn in members of the subset and cheer when they succeed in their terror attacks truly innocent?
Perhaps impolite is not the right word. In engineering college, I “befriended” a group of Muslims and dragged them through the class. I have never seen a group so ill prepared for college. They not only didn’t grasp the math, they actually believed in magic. Allah was the answer for anything they didn’t know about; which was a lot. So, I expected to be treated well when I couldn’t attend the class before the final where the teacher told us exactly what to expect so we could write a page of formulas. When I got my Muslim briefing I felt a bit odd as their body language made me uneasy. When the test was handed out I realized I had been lied to. I looked over at the massively muscular Arab who was their “leader” and he laughed. After the test I asked why they had lied. He poked a massive square finger hard into my chest and said, “You look bad, ‘we’ look better.”
At of my jobs I had worked hard with one of my subordinates, a “moderate” Arab. One day in a fit of anger he said, “You will not like it when ‘we’ take over. You will be my slave and you will pay me taxes.”
My Arab doctor, too is polite. But then again, I am his customer. The guys in my classes were polite, but then again, without me they’d all have failed. My subordinate was the perfect employee; always happy and smiling. One day I asked him why he had so many children and he said, “We must have soldiers for the Jihad.”
So, you are correct, “polite” isn’t the word. But I don’t know what other word to use.