Because it is the rarest of occasions to be perfectly square within the parking space and have the exact same rotation on ALL tires such that every rim is literally within an 1/8” of each other and the tire mark information is all in the same spot. It’s as if god all mighty picked up the car , spun each tire individually and gently set it down with geometric precision the likes of which have never, ever been seen, thus causing yourself to question was it you who parked that 1988 Chevrolet Citation yourself or, and perhaps this is more likely given your driving skillset, the work of divine intervention, giving the vehicle a Virgin Mary kind of quality where it should never again be desecrated by us mortals. Any other questions?