My thoughts exactly Ian. How farmers can be allowed to drive around with the sort of weights they do without the kit carrying it being checked is beyond me. Especially when you look at some of the trailers in use! I wouldn't trust some of the kit I see to carry it's own weight, let alone a load of bales!
I suppose if the owner knows what he's looking at and does his own checks then it's ok. I'd imagine the likes of moose are quite capable of judging the state of a vehicle, but not everyone knows all the checks and I'm sure many don't bother at all. One of my brake lines on the mog was nearly worn through and I hadn't spotted it even though I'd made my best attempt to look over it. That's part of the reason for my calling the mechanic out to go over it for me.