oh it is "recyclable", just (for several materials) takes more energy to recycle it than toss it in a landfill. You get to feel good that cardboard gets a "new life", instead of a new one (which extracts more carbon from the atmosphere) being created, we can burn more CO2 to have a second truck travel down your street to pick up renewable cardboard and haul it around town till it eventually gets cleaned and processed (at the cost of even more energy).