Status, Parker, Flaxwood, EGC, Ampeg, Steinberger, Rainsong, Composite acoustics. It's been tried and is still happening however you run in to various problem such as - Guitarists don't like change. The materials/time to make certain non-wood instruments often leaves them being very expensive and either not justifiable to make or not justifiable for any player. Some materials make things heavy such as acrylic/resin. It's more expensive than cheap wood, like the cites rosewood debacle, we just got cheaper wood from some companies and other companies admitted that ebony isn't actually that expensive and put it on their models. Some companies that make "woods" that are sustainable are small (Rocklite, Richlite) and may not be known to large builders. You have a company like Parker in which every guitar is so complicated to make it makes a very unsustainable business. It's been tried, people are still trying. But no ones going to buy a Les Paul with a Resin fretboard.