I don't feel that the original post should be converted into a Discussion section post; I believe it should be privileged because it stands alone, while this post does not.

In general, I consider posting lengthy replies to Main section posts as their own Main section posts quite undesirable. Consider what LessWrong might look like if this became a common practice-- original Main section posts would be outnumbered by lengthy replies to them, making it difficult for new and interesting conversations to start.