There is a certain amount of mystique in owning an Airstream. Status perhaps but I think it is more than just that. Why do some strive to own a Harley Davidson when they can purchase a very good motorcycle for a lot less money? Why do some like Apple computers over a less expensive PC?
I owned a Starcraft white box before we got the Airstream. Pulling an Airstream is a totally different experience. We do not live full time in our trailer and usually go out for 6 weeks maximum. When we do camp/travel I don't expect all the comforts of home. If I wanted to sit in front of a fireplace I would not leave home. Our Starcraft also had a slideout and while it did provide lots of room it was also problematic.
We are not large people and we travel light. My biggest complaint is that the Airstream does not have much storage, especially exterior storage. Like they say, for the price, you should have a place to store a couple of lawn chairs.
As far as a "weak frame" is concerned I really don't agree. They are built different and the strength comes from the shell and the frame acting as one piece. When people try to bolt on or weld additions to the frame to hold things like generators and extra storage containers they are really going to mess things up. The white box is built on a frame and the frame alone has much more strength because it has to hold the entire trailer. As far as having loaded tanks causing frames to break, I doubt that this is a common problem.
The shells are made of aluminum but they still can and do leak especially if the owner does not maintain them. The water makes it way down to the wood floor where it will rot out. A big white box can leak too but the rot will usually happen in the roof structure or the side walls first. When stories of rotted floors surface they are usually in older Airstreams but not always. When stories of rebuilding a 65 Airstream surface and talk about rotted floors and rusted frame members are shared please keep in mind that these trailers are almost 50 years old. How many 50 year old regular trailers do you see on the road?
The end line is, there are lots of different trailers out there because there are lots of different people camping. I like my Airstream but I will be the first one to say they are not for everyone.