My impression of this phenomenon is that the person asking the question is usually looking for validation of their own opinion rather than seeking an objective second opinion they want to listen to. In many cases it is harmless but it is bad manners, I don't like it either. They would be much better framing it like "Hey, this is what I think...do you agree?" rather than "What do you think? No, I think it's like this instead"; pretty much the same conversation content but an entirely different conversation experience. Communication styles can completely alter a social interaction in many ways.