Why do some people feel the need to piss all over a question when they aren't actually answering the question (examples in details)?

Sorry if my question isn’t clear, I’m a bit tired. Here are some examples of what I mean.

Question: “What’s your favorite country music song?”
Answer: “You’d never get me to listen to country music. Country music is for rednecks.”

Question: “What is your favorite sport?”
Answer: “I hate sports. I’d rather read.”

Why do people do this? Do they need to make their point that badly and put others down for what they enjoy, especially if they aren’t actually answering the question?

Believe me, I’ve wanted to do this before when I didn’t like some generalizations being thrown around on a question, but I knew I wouldn’t be answering the question. I would have derailed the thread, so I left it alone.