Everything can fail and will fail given enough time and hard use.
I worked as a test engineer in a group with applied mechanics engineers and stress analysis engineers for a global machine manufacturer. Even with advanced FEA, and physical stress testing, we'd still have failures in the field. I can't imagine some of these small, consumer grade, boat manufacturers having the same amount of resources to do this level of virtual and physical testing.
They may not even fully understand the load cases. At least that was my assumption, after hearing about all the welded boat failures from friends and co-workers.
