"The following are the 29 classes that compete in SCCA Club Racing National events. In some cases, the cars in the Club Racing classes have a sister series within the professional ranks"
Copied he quote above from the SCCA website. For me it sums it up very well. Many classes, low visability, amateur sport. Also similar to minor league unaffiliated baseball, many teams, many leagues and players living out the dream.
Think Joe NASCAR would pay NASCAR ticket prices to see offshore/inshore racing ? Would Joe NFL or NBA or NHL pay their ticket prices to see offshore/inshore racing ?