By the same token, shouldn’t the JS board have its own site named DDBS ?
You have a point, but they're totally different. JS was intended to be DDBS from day-1. It was never meant to be purposeful. To quote the line under the board title, "Visit this board to kick back and talk about anything
worthless". Key word here. Deals boards, OTOH were intended for useful posts that basically sift through all the garbage sales and post the good ones here. If all the garbage seeps through, we might as well have the entire board consist of two links,
this, and
this. וזהו!