I think its something related to the latin character, and its something very difficult to control, specially for some people. It happens to people of some South american, Spain, Italy and probably other countries with latin roots. We are warm people, and speak very straight, direct to the point and sometimes using a vocabulary that can be considered as rude, but its not intended to be rude, an example:
You see a friend and you wave him like this: "Whats up, son of the b*tch?" And its not you are insulting him, is just like saying "what a great guy are you, whats new?" I know it sounds strange, but its true
As a spanish, I learnt how to control my manners when writing and talking in english, as its important to learn that english is generally speaking a more polite language, and generally, non latin people are more polite as well. Thats what happens with brasilians, for example, they go straight to the question and with manners that are considered as rude to the rest of the people, but sometimes is not rudeness, its just the way they talk. I see it in many questions sent by many spanish fans, some of them are asking in the direct way, putting them on risk of being rude, and some learnt how to write in a more polite way, thinking not in you as the "writer" but in the "readers" of your message.
Anyone understood anything I said?