Because he said he didn't want to play the game for "thousands of hours." If you don't like the game that much then don't play it that much. I'm sure I will eventually have nearly every car in the game and I don't "grind." If it felt like a job I wouldn't play. I enjoy every lap because it's a fun game to play.
I really doubt you’ll ever have nearly every car if you don’t think it’s a grind. Something has to change if players are to accomplish the goal of collecting all cars without resorting to a mechanical grind, as Kaz puts it.