Uhhhhh probably in any sport the majority of people don't really have a real interest in the sport so much as the event. Baseball season ticket holders are notoriously bad, to the point where sitting in the best seats also means sitting next to someone who isn't even watching. College fans probably don't know their entire starting lineups in basketball, much less so the bench players. College football is all about the traditions and shit. I mention all this because as horrible and dumb as Nascar is, its fans probably aren't all that worst than any other sport. Everyone shows up, drinks if they can, eat, and hope their favorite player/racer/team does well. Crashes are probably just as much a draw as fighting is with hockey. I will say though that I bet Nascar fans don't have all that complex of an appreciation but most fans in all sports don't.
Also there's nothing interesting about a player getting injured in any sport because its just them on the ground and takes away from the game.