Redundant "quick reply"

Perhaps someone can explain to me the purpose of requiring us to click on the post quick reply button before we can reply to a thread in the box that is already located at the bottom of the complete thread. It seems redundant to me to do that as opposed to just having the ability to begin typing in the quick reply box. Not that it is difficult, of course; it is simple to click on the button. It just seems a bit redundant to me.