Because it's a design fault with the unit?
ls it acceptable for a Ā£50,000 vehicle to be scrap after six years and 36,000 miles because of an inherent design flaw in the engine?
Absolutely not, but unfortunately, car manufacturers have been getting away with this sort of thing forever. The engine is I believe, Peugeot supplied, so if that's the case, it isn't necessarily a "design flaw" per se, but more a misapplication. Quite frankly, I think that engine is the wrong power unit for the application and that's why they break; just not strong enough.
To successfully bring JLR to task would take a considerable amount of money to take it through the courts. That would require a committed, strongly financed, group of affected individuals who could stay the course. JLR (and other corporations) has the time, money, and motivation to keep this type of legal fight going on for years and thereby preventing the plaintiffs from winning their case. It's also IMO why JLR do cover or contribute to some cases, as it stops those disgruntled customers from getting together and organising themselves into a credible group that could mount a formal legal case against them.
A prima facie case that the engine is flawed design wouldn't get far, a ton of supporting evidence to back the claim would be required and that would require a lot of money spending to compile. Engineering reports on the overall design, of the components used, the various other parts suppliers and sub contractors involved, full technical analysis and inspection of the good engine and again, for the failures. It would cost thousands and then millions, and take years.
It's not going to happen!