I have actually seen and experienced a little those sorta road conditions over your way Gwolf (I lived & worked in Seattle for a while, and extensively toured the NorthWestern States, as well as visiting/touring quite a few other States on the East Coast & across the South of the US, just not so much in the middle/North...

), and in a lot of other Northern Countries too; and I'm still firmly convinced that the vast majority of your road network is
FAR BETTER than that of most, and certainly that of the Oz road network; while the 'really bad stuff' you mention (which is still better than a fair bit of our 'good' stuff) is found on a
tiny percentage of your road network, and I suspect that
most US Spyder Riders tend to avoid those bad areas/sections as much as they can anyway.
Here in Oz, even for those Spyder riders who religiously avoid riding off the blacktop, if you want to ride pretty much anywhere/on anything but our Highway 1, which goes around the perimeter of the Country, you'll really have no choice but to spend quite a bit of time riding on roads that I
never saw the likes of over your way, apart from the odd bit of damage that was already being worked on and except for when I got to go out 4WD'ing and we went 'off road'... Some of the '4WD Only tracks' I travelled on then were in significantly better condition than many of our 'Secondary Highways'!
Talk to PeteOz about it - he's gone so far as electing to quit riding completely, largely because of the condition of all/any of the roads in his area, and how much that was detracting from his riding enjoyment!
But the point of my post was that the swing arm mounted hitch is a very poor design choice that is contributing to a LOT of trailer damage - how much harder/more expensive would it have been for BRP to design/manufacture a hitch mount coming off the sprung frame somewhere, or even off the leading swing arm bush mount area instead of the continually moving and un-sprung rear wheel axle in such a way that it pounds any trailer to death on anything but the smoothest of roads?!?