I used to think that too, but there are too many of these, from engines, to cracking suspension members, to airbags, etc. that indicate to me there is not enough actual testing done, in all operational conditions. Even ongoing issues, like LSPI and fuel dilution from DI should have been found and fixed before those products came to market. Lifter problems, cylinder deactivation, spark plugs becoming projectiles, Theta bottom ends. The list is long, and getting longer. Instead they were tested properly in the field, by paying customers, and simple solutions found, or if not, the question gets raised, "I wonder why did they do it that way? Didn't this issue come up in testing?"
Just my $.02.