IME the only thing that can cause this kind of wear (not counting being used exclusively for the mt. Washington climb) is rust. If you ride an unlubed or poorly lubed chain in the rain, the water can wick in and attack the pins before it dries completely. This speeds wear, and can happen even if there's no surface rust visible.
However, I suspect that the OPs problem isn't wear as much as high readings on a gadget.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.