Boarders also DO need to carry at least one pole to help get across the flats...
Much like when I go tubing I bring a kayak paddle for improved navigation and maneuverability.
Ive been riding for 20 plus years. When I get stuck on flats I either push with my back leg, un-strap and walk, or have my skier wife tow me - and thats in order from first to last resort. Never have I seen anyone on a snowboard bring a pole along.