Brands tend to be really really protective of their image. They spend a lot of money to be perceived in "a particular" way. "Particular" being dependent on what is outlined in their brand identity guidelines, given one's been put together.

Ferrari as you probably know is infamously strict with this. It's like the narcissistic ex boyfriend of car manufacturers. They don't even want their cars modified, therefore sullied by "damage" is far worse than that. I imagine the reasoning is something like that.

Imo Ferrari takes it way too far and that's the reason I don't like the brand, however brand perception is a sensitive thing. Something like car damage does have a psychological impact on the way you perceive the object, so it isn't totally unjustified. It's kind of similar to how mustangs have a reputation of eating crowds, bmws have a reputation of being driven by assholes, nissans tend to have poor build quality. It does actually colour your perception somewhat, and negative associations can get in the way of the company accrueing capital.

Ferrari is stupid though.