May have been built as an Amish cabin to start
I wonder if those metal joist hangers were too high-tech for the Amish
This is indeed the strangest Romex installation I seen.
It can also be a hazard if a dog chewed on it. I had a dog that chewed on the wood trim around the doors, I am sure she would have chewed on the Romex if it was open like that. Also a small child may pull on it. The guard strips are a good idea, but will need to be covered to protect it from sunlight.
It would be good if the code was more specific, like any Romex exposed less than 6 feet from the floor needs to be protected. That will solve the judgment question of "subject to damage" in many cases.
I imaging some local codes may say that. It doesn't really apply in my area, since Romex isn't even allowed at all.