Vick, it sounds like you haven't paddled a real packraft (which at the moment only equal Alpackas, or the NRS boat).
I would indeed argue that the weight, packability, versatility, and range of water that can be navigated in a packraft make them a functionally different category of boat. They look like other craft, but they way they let you travel in the wilderness is quite different.
Packrafts are like skis or mountain bikes in that they're efficient machines for moving through the landscape. All are utilitarian and amusing. Packrafts get special attention because they're the most efficient and universally applicable of technological aids to wilderness travel.
River boards are to packrafts as mountain unicycles are to mountain bikes.