The thing I find really interesting about your post and my reaction to it is that you frame #QT as talking about a person while I'd see it as very explicitly talking about the content.
If I quote something and expand on it, the major reference is to what was said, not the person saying it. The person is only included as an attribute, but the content takes center stage.
And to me that's the major point of QT: it takes some specific content and builds upon it in ways that can't really be done through other means.
QT isn't about the person. It's about the quote, and sort of furthering human knowledge by taking what a person has expressed to another level.
But then, I'm an academic, so that's just daily life for me :)