Most of the time, initial answers need to have minor adjustments in order to have proper grammar and correct spelling. Furthermore, answers are sometimes incomplete, and can be elaborated on to better explain the information being presented. More so, there are discussions, and so a multitude of contributors need to provide an answer. There are also occurrences where the original answers are incorrect or too confusing to understand. Lastly, sometimes original answers don't actually answer the question. They either ask the original poster something back, (e.g. Why do you want to know?) or give unsure answers (i.e. I dunno. Maybe?).