Welcome to capitalism.
It is all about Marketing, and those kits are mainly marketed to Trailer Queens that will never drive a mile. Nice bling though.
Same deal with the stainless braided cover and AN nuts (fake?) over the coolant hoses. Not really functional, but impresses. I would be impressed if someone could fit formed silicone heater hoses (after-market for Mustangs and rice cars) with it looking like a factory design.