By being able to withstand this kind of extreme abuse without any sign of catastrophic failure, wouldn't that make it over engineered and therefore probably heavier than strictly necessary?
It's been said, in the yacht racing business, that if a boat makes it across the finishing line with the hull in one piece, it's been overengineered and next time the hull should be made thinner.
Personally I would prefer for relatively useful items like the landing gear to be a bit stronger than that.
Knowing a TB20 fairly intimately, I don't think it is overengineered, but it is well made. Socata build quality is noticeably better than most GA types. In fact, looking at the speed, range, and fuel flow, versus cockpit dimensions, there is no evidence of excessive weight on any of these types.