I think a lot of it has to do with people simply not used to someone being so blunt about things. We're taught to always be nice or keep our mouths shut if we don't have anything nice to say, we're expected to constantly be polite. So when you talk to someone that is incredibly blunt it's a shock to a lot of people. Combine that with how easy it is to misread emotion in text and it can create a false impression of a person and their intentions.
tell me about misreading emotion in text. Have gotten yelled at plenty of times by my girl, WTF I didn't mean it like that situation. LOL