Well, in the dream world posited, anyone who attended would be a real enthusiast, because those "name" drivers would not draw a crowd! Being a reserve driver does not provide the path to the top that it once did. Remember when there were test drivers, and they actually got to drive the cars?
Non-championship races were regular events throughout the 60s, but with the teams' front line drivers behind the wheel. Also quite a few independents with year-old F1 cars and abominations like Cooper chassis with Ferrari V12 from a road car . . .
Enzo Ferrari was a great man. But he was not a good man. -- Phil Hill