Well, in many of the tech-world boards I belong to, they force the "quote-on-the-bottom" style because, especially if it is a long post being quoted, the user may think "oh, I've read this already" and skip it. The assumption is that you are reading the thread as a contiguous block thus, stylistically, the quote does not need to be there at all if it is replying to the most current post.
In the case where it is not the most current post, the quote is there more for reference, again, assuming you are reading the thread and just need to get your "bearings" of what is being discussed.
If putting the quote below the response is outlawed, only outlaws will put their quotes below their responses

Have it your way...just like Burger King.
Best,
M