My old man ran his farm truck with a bad wheel bearing for almost two months. He called it his "angry bee" and just turned the radio up. I used to think that was just him being stubborn, but after seeing that Powerstroke story, I get it now. People just adapt to the noise when they don't know what it means.
Honestly, I get it though. Some folks just aren't car people. My neighbor drove his truck with a rod knock for weeks, said it just sounded "thirsty". He was just commuting and figured if it was still moving, it was fine. People tune out weird sounds all the time, especially if the truck isn't their main hobby. They just don't know what's normal and what's a five thousand dollar warning sign.