Immature people

Why is it that if someone is even the slightest bit offended by a question you ask them they block you? Would they do this in IRL or would they tell you that they are offended by it and give you the opportunity to apologize. Afterwards you may mutually agree to either stay in touch or not, but at least you do so as grown ups. I just don't understand the lack of maturity on this and every other internet site.