Why Are American RVs Built So Cheaply?

I realize that most RVs are only built for summer. But yet there are literally thousands of RV owners also using their rigs during winter. Like us, they are facing quite a few challenges. Challenge #1 is the incredibly bad insulation of RVs. Just to mention a few spots where improvements could be done without incurring much of a higher cost. - Compartment doors have no insulation whatsoever - entry doors are often having gaps to the frame - Slide-outs have the thinnest walls of the RV - Aux. showers are installed in a cheap plastic box with no  insulation behind it. - No insulation where outside water inlets are crossing the wall - Underbellies are generally only covered with a thin tar paper, instead of using hard-backed high density foam. - No insulation at the power inlet Now, I know that RVs CAN be delivered with double pane windows, but fact is most RVs on the market have left the factory with single pane windows. European RVs have been manufactured with double-pane PLEXI windows since the early eighties. No condensation problems there! These windows are also light-weight, with “light-weight” being a good point in most RV-sales over the recent years. And speaking about light-weight RVs, one has to wonder about the heavy-duty truck-style welded steel frames American RV-manufacturers are putting under their RVs. Aluminum frames WOULD be more expensive but would also make a significant contribution to make the RV light-weight. That in turn would lead to that bumper-pull trailers could be pulled by smaller vehicles. But I guess if consumers don’t demand changes, change will not come from manufacturers. Have a comment? Let’s have it and thanks for hanging in here.