Why Not Use Wood?

Although the Porchboard was originally made from mahogany we soon discovered that the type of wood used had no effect on the sound of the instrument. Today, Porchboards are manufactured from composite decking made of recycled plastic bags and hardwood sawdust.  (Trex)

The choice to go green with this material was easy.
One, it's more durable;
Two, it's green; and
Three, we can,"

Why not recycle if you can? It doesn't affect the sound and it saves the beautiful woods for guitars where the sound is affected.