Its like how teslas are referred to as “a tesla” and any other brand as “a car”.
There are a LOT of car brands that are "A <car brand>" and not "A car". In fact, "A car" is Toyota, Honda, Kia/Hyundai, GM, Ford (most of them anyway), etc.
"A <car brand>" is "A BMW, Tesla, Lexus, Acura, Mercedes, Audi, Subaru, Porsche... "and several more (any brand more premium than those I just named).
I do think a large portion of this is tesla not wanting to deal with the press around salvage cars though, as well as "we control our product chain and we dont have to, so we wont unless forced by courts."