"Let the debate start?" What debate? What is there to disagree with?
Ticket prices are cheap for undercard divisions (truck, Xfininity) and I'll bet in some cases you could get a free ticket is you stand somewhere near the entrance gate/ticket window about an hour before the race starts.... (yup.)
Passenger cars are more difficult to work on... (yup.)
Young people aren't interested in cars the way we were. (yup.)
You won't find young people at a car show that caters to old cars/older people (especially when they have a DJ playing 50's music, and where in some cases, the club holding the show does not allow anything newer than a certain year.... (yup.)
No need to spur folks on with "let the debate start." Folks may want to add to the list of reasons, but don't think there's much of a debate to be had with the points you've brought up.
The real discussion is, is there anything that can be done to improve things when it comes to truck, Xfinity and cup?