I think it's simpler than that. Bubble wrap the wrong way round means the only air cushioning is provided by the bubbles, and all the space between the bubbles

I think it's simpler than that. Bubble wrap the wrong way round means the only air cushioning is provided by the bubbles, and all the space between the bubbles is just a thin layer of plastic flat on the object that needs protection. Bubble wrap the right way round means the object is air-cushioned from the outside by both the bubbles themselves and the space between them (with the added bonus of the wrapping keeping a flatish outside surface).