Quality of assembly, quality of materials and quality of design are three different things and all three need to be in play for the formula to succeed. It is the same in automotive world as in the RV industry as it is in the small appliance industry.
Most of the main stream products we buy are assembled by robots and that can be done due to platform interchangeability and outsourcing sub assemblies from other manufacturers. Resulting fairly high quality of assembly, not so in the RV industry. Quality of design should be equal in most cases, as the computers do most of the designing in today's society. The real culprit here is quality of assembly, think about any high end market item made in Germany vs a similar product from China. While they look the same, they aren't even close in quality.
Marine grade plywood vs OSB, 1 inch walls vs 3 inch walls, hourly wage vs piecework pay. These all result in a very different but similar looking products.