1. NASCAR is still seen as hick sport. People laugh at drivers and fans, it's the butt of jokes in most circles. On the other hand you have F1 that is seen as sexy, fun, and something to be enjoyed by the elite.
Basketball, football, baseball have many many high profile fans, it also helps that many of the players themselves are among common gossip blog fodder. The most high profile person in NASCAR is Jeff Gordon..... he doesn't even drive anymore and that's a problem. He and his wife are constantly elbow rubbing with the Hollywood and social elite. Dale Jr, the most recognizable, is smoking meat and drinking beer on the weekend.... Up and comers Chase Elliott are Ryan Blaney are drinking their way through Ireland, hunting, and putting out pod casts. Bubba is on a cringeworthy campaign to get sucky pizza companies to sponsor him.
Now look at other sports:
Lebron James sat ring side at the biggest fight of the year, is covering GQ this month, and is creating a TV Series (his third btw).
Lewis Hamilton is front row at fashion week shows, is constantly hanging out with A list celebrities, going to movie premieres and has some incredibly lucrative endorsement deals.
Serena Williams (is on maternity leave) is generally seen hobknobbing with A list Celebs, was on the cover of vanity fair, did a TED talk, and has her own very lucrative workout brand.....
NASCAR has relate-ability problem and not a single person over there is even trying to fix it.... instead they are trying to show they are still one of the good ole boys, but the good ole boys aren't spending the money or giving the exposure needed to keep this sport alive.