I would speculate it has a lot to do with the time of the year; kids are still in school. Combine that with too many series at the top level competing for a pretty small percentage of racers and you get lousy turnouts. Just look at the results of the WKA Winter Cup at Ocala two weekends ago, 67 karts total. And now I read today there’s talk of a Skusa Winter Cup, seems like trying to extract more blood from the stone to me.
On a positive note I was at New Castle yesterday for their second club race of the season, 191 entries by my count. Goes to show grass roots racing (LO206 made up about 90 of those entries between 3 classes) and affordable entry fees will still draw big numbers.