I certainly always get the impression that the xw "limit" was more about how far the test pilot was prepared to push the aircraft during testing and the level of wind at the time (apparently the Tristar's autoland would be certified for a 35+ xw if they had found such a wind at the time) rather than a true reflection of how good the aircraft is. The Bulldog for example has a demonstrated figure of 35 which is insane for a light aircraft, but part of that is surely that the test pilot on the day had the 'luxury' of a 35 knot wind and was maybe a little bit braver than your 'average' test pilot.
The PA28 can take more than 17knots (as I discovered doing solo circuits during my PPL
). But the Cub I would never, ever push beyond its limit.