Living in Ohio (no inspection "rust belt" state), I saw a minivan's axle pop loose ahead of me on the highway, which sent it into the concrete barrier pretty much instantly. Perhaps you don't have rust issues where you live, but requiring some minimum mechanical function to register a car should be everywhere in my opinion. Generally inspections are either mechanical/safety or emissions. Emissions are based on the car model in every state I've lived in, so as long as you don't modify your car to blow smoke it'll pass. Mechanical inspections are to make sure there's no major rust, the brakes work, the lights work, tires aren't bald, etc.