See, its all in the interpretation of the charts
Actually, I don't remember the fall off of FF entry when I was running them (1980-1985) until the DB1 showed up in late 1983-1984, but then I don't have the stats other than that chart you posted. The fields were huge both at the regional and national level in the NE and always had their own run group.
On the topic of overall entry...I had no idea of the growth of entries at the regional level during the period, and that would certainly make me change my other statements.
I like the idea of the FIT, regardless (even if it isn't my sandbox).