Well, not that it is my favorite sport, but F1 is far more popular throughout the world as compared to NASCAR. F1 races throughout Europe, Australia, China, Japan, Brazil, Canada,Bahrain, Singapore, etc.
Mario Andretti and Dan Gurney only contested a few NASCAR races opting to compete in Indy Car and Formula 1 which were more popular at the time.
Who has defected to "real racing"?
If you are speaking of Juan Montoya, well he was fired while driving in F1. Other Indy Car drivers are just going to a higher paycheck as Tony George ruined Indy Car racing.
None other than TS have been successful! Sorry they're all defecting to real racing and your sport isn't nearly as popular. You're too dense to even talk to. Have a nice day.