Probably because it’s cheap and lasts. Doesn’t make it right. There’s still a huge amount of shock going into the mounts. If one is doing this on their own, may as well do it right.
It’s worked fine on my 7 year old trailer. Where as the straps on my Fontaine only lasted 3 years. The chain isn’t attached to the mount. It goes from the trailer frame to the swing arms. No shock on the mounts whatsoever.
How is the chain mounted? There are no tabs/mounts the chain is bolted to. Again, nylon strap material subjected to constant elements doesn’t last forever. I’m not denying that. What I’m refuting is the constant shock. You don’t feel it on the trailer, but, on the truck’s chassis, you’ll feel that dead stop through the chassis, guaranteed.
Welded. There is no constant shock because of the slack in the chain. It only gets tight in an over extension scenario
I bet those chain are getting used way more than you realize. Our roads are just complete crap. Going up onto a bridge, then, back down off it is stupid. They’re big suspension events that shouldn’t be. Bridges and transitions should be ground perfect. Likewise, concrete sections failing and dropping down create massive suspension events. The nicest riding equipment all gets thrown around. I run across Indiana I-70, everyday, and watch how everything rides across that POS road. Afterall, I have nothing else to do, but look out the windows and think.