I'll look through the prism of thrifty recycler ...
If the buyer can't figure out it needs a box and possibly stuffing, to be used ... then the Stupidity Meter would start pointing to the reader.
The seller does say it is "complete, minus cabinet. sounds great!" I guess it can sound stupid depending on how you read it and with the right inflection. Reminds me of Kramer in a Seinfeld skit where he has to rehearse his single line for a movie. In fact, AK reminds me a lot of Seinfeld lately.
Anyway, I'll give the guy the benefit of the doubt. Perhaps targeted and enough to interest Do It Yourselfers to ask further questions.