Why are Truck Campers so poorly made?

I hear you Avion69, The article went in to great detail on the man who began airstream in his back yard. And it talks about when the trailers were made longer with the Bathtub in back how the rear end droops down and gives the years when all this takes place. Its a good read and may already be here on this forum but here is a link for anyone who likes reading about the history of these amazing creations. http://www.calldon.com/air.htm It has some really good info on the years and lengths also.
You will have to copy and paste the link I guess I cant get it to work right, But its worth the trouble.