Too many people are not smart enough or don't care enough to consider the subtext of what is said. This leads to a country in which the words you use are more important than the meaning behind the words. For example:
Several years back I had a coworker who was verbally abusive. He was a pro at making everyone around him feel insecure and unimportant. But he was very careful with his word choice and complaints to HR were ignored. One day I had had enough of his bullshit and responded to him with, "Oh fuck off." I was written up. Now in the context of the situation, whatever it was that he said to me to trigger such a reaction was worse, and other coworkers of mine would back that up. But to the HR person, my choice of the word "fuck" trumped whatever else was going on in the situation. Oh, and a good number of people in the US seem to take pleasure in being offended by things. Even when something shouldn't be offensive to them, they will take it as a personal attack.