I don't think I've ever come across anyone who uses it in all the drawings I've gotten from other companies.
Like you, I doubt most people know it's there. I had to search the help file to find where the box was, after reading your post. I knew it was there somewhere, but couldn't remember where. Took me long enough that Slim answered before I found it.
I just don't think many people care to see it like that. I'd rather do a print-preview, myself, to see how it'll look plotted. 1) it puts it on a white background as opposed to the black background I keep layouts/paperspace set to and 2) the lineweights seem much more accurately represented.