I do believe that all manufacturer's ( all products not just caravans) should ultimately be made liable for manufacturing substandard products, but here in the UK there are at least two major legal barriers placed between the consumer and the manufacturer that prevents the consumer from normally taking direct proceedings against a manufacturer.
The first issue is our Consumer Rights in various guises, where liability can only exist between contracted parties i.e. customer and seller. This sets out a perfectly good argument that sellers should not sell faulty goods, but this basically shields the supply processors and the manufacturer from the problems they cause the end users.
And the second factor is even more contentious, and that is the the way consumer rights sets out the notion of what constitutes a fault, and how " reasonable durability" or "life expectancy" are established in the context of the product in question.
But in the case of caravanning, we see from reliability surveys that customers find significant faults in about 20% of new caravans that have to have some form of remedial work carried out under the manufacturer's warranty policies. By the standards of any factory manufacturing process that is a very high attrition rate, and some of those faults are indicative of inadequate design and development or uncontrolled assembly procedures, and despite years of similar evidence the industry has not taken effective action to reduce this crazy combination of waste of time ,resources and money, and disruption it causes to their end users and dealers
But there is also an insidious range of other less serious faults which go unrecorded, because UK caravanner's have become so used to having to put up with manufacturing faults in caravans, it has become an accepted norm that small adjustments or minor repairs will be needed after relatively short periods of ownership, and so do not get recorded.
It's this historic pattern of poor reliability which seems to used to suggest a caravan does not have a long life expectancy. Yet we see many caravans still in active use at age 10 to 15 years often having had to be repaired to correct leaky panel joints and fittings.
Where panel joints and leaks are often the problem, the manufacturers more often than not seek to blame the end user for driving over "unsuitable surfaces." There may be a few cases where this is true, but the majority are just driven over the normal UK roads.
If cars fell apart in the way caravans do there would be a massive outcry. But the fact cars don't fall apart even after doing tens of thousands of more miles than most caravans simply highlights how far behind caravan design and testing is from the realities of real life.