What happens when you give your truck bed spray cab a good bang against something and then the wood gets exposed?
Doesn't happen w rat fur.
For me, that seems more like a case of why plywood is preferable over MDF. When MDF cracks, the sealant properties is lost, and it becomes hydroscopic. It swells, and begins to tear itself apart. More so for the cheap asian MDF.
Tolex and truck bed spray have better sealing properties than rat fur. Some manufacturers of MDF cabs just use the glue for rat fur as the sealant to save $.

