So many “journalists“ and “technologists“ said the same when Apple entered the phone market. Now look at it. Arguably one of the most important markets in the world now. They completely disrupted the camera, GPS, retail shopping, and entertainment markets.
Could a car tarnish Apple’s brand? Yes. Could it put Apple’s brand even higher in to the stratosphere? Yes. They just have to do it right. How much did Elon know about cars before Tesla? What’s Apple’s longterm plans? We don’t know. Heck we don’t know officially if there is even “a car”.
Do car companies fail? Sometimes they do when they are poorly run, or forget about their target market; Saturn, Pontiac, Dodge. On the other hand no one at Hyundai, Honda, BMW, or Jeep are standing in soup lines.