Why are some peoples answers so rude on here?

Two out of three questions that I post on here I will get someone with something rude to say. I'm not even asking questions that are offensive. Why do people take things so personally and answer so rudely? I know there are a lot of really dumb questions and that some people are looking for really dumb answers but those are normally very obvious. I wish people would really realize that some people (like me) are asking sincere questions.