Loads of guitar makers have used different materials to great effect; Dan Armstrong, Danelectro, James Trussart, Parker Fly, Martin, Rainsong etc.
I don't see any problem with Gibson using alternative materials, they probably have to anyway after their recent troubles with importing wood certain woods. We should at least give them a try before deciding and not get too hung up on the particular shade of wood.
Surely if these materials sound good then they are good?
I suppose there was a similar resistance to stopping using ivory at some point in time.....