Answer:
Because we are human
Explanation:
As humans, we can be disrespectful and mean. Although you saying "Even though you didn't do anything wrong" could be wrong. There are times when people can be mean or disrespectful without realizing they are doing it. But if a person was really being disrespectful without a reason then either they might just want to be or there might be something going on. Don't just assume things. Plus they probably don't have an "urge" or be disrespectful. That is going a little far to say some people have the "urge" to be disrespectful.
