Where do I start?
Geez, Cockney Steve
Where do I start? Firstly, remember the "Phillips Explorer", the multi-hull vessel that was designed to circumnavigate the world in 80 days and then had a "structural malfunction" in the English Channel just after Lizzie launched her, and then sank in the Atlantic on her maiden voyage? (Shades of the Titanic).
There are vast differences between structures restricted to water travel where weight is not as critical and margins of safety are far more generous and aircraft where margins are much more finely managed. In a marine environment, a bad repair may involve a desperate resort to a dinghy and activation of an EPERB but in aircraft a bad repair may have far more significant ramifications. You have no life raft and you can not swim for long in air.
As for the "air-fix" comment, it is difficult for most people to comprehend that almost every aircraft anywhere has some adhesive bonded structure and in my (extensive) experience in adhesive bond failure forensics there have been an inordinate number of adhesive bond failures to metallic structures, so casting aspersions towards a "plastic" or "bin-liner" structure shows a neanderthalic ignorance of structural materials. There are even more significant deficiencies in bonded metallic structures than there are associated with fibre composites.
Next the "too-strong" comment. In reality, the problem of load transfer is not strength related, it is stiffness related. A compliant-but-strong material (like fibre-glass, high strength but low elastic modulus) will not cause as much load interaction as a stiff-but-weak material such as mild steel (low strength but high elastic modulus). Stiffness causes load redistribution problems, not strength.