I don’t know if the design or the materials were inferior. I think there’s a reason we don’t make the roofs of American airport terminals out of Styrofoam, however....
It is standard practice to glue a rubber roof onto rigid insulation fastened to a metal or concrete roof deck. Just about every commercial roof in America is made that way. There are standards for correctly fastening the insulation to resist uplift loads from wind. The insulation is not a primary structural element. I doubt the Chinese use it as one.