Okay, it's wood but OMG what a super-schitty job of insulation. Sad!
That's what most ceilings look like too as far as insulation goes. Doing a job correctly doesn't take more time if the installers are adequately trained. Lack of regulations and inspections contributes. A TT manufacturer could care less if they can get away with it to save a buck or two. Very sad!!
I too would gladly pay more if I knew improved quality was included but there is no yardstick for measuring and comparing quality.
RVs are incorrectly designed because they have no vapor barrier on the interior side of walls and ceilings. When campinig in colder temps. and measures are not taken to remove warm moisture laden air, it migrates through luan and insulation to the exterior skins or ceiling membranes where it condenses and can lead to delamination, rot and mildew. You'd never ever get away with this in building construction. Again, it's done simply because it's cheaper and they can get away with it. As a P.Eng. that used to work in building constr. (now retired) and an amateur car restorer, I am APPALLED at the way RVs are designed and built.