I cared about it because it was a series that gave young drivers a chance to gain exposure.
For example, Formula BMW used to run at Indy on the F1 weekend (when Indy had F1, that is - don't get me started on that issue ; -), there was a lot of high-powered, read moneyed, folks watching, and a good young driver in Formula BMW could catch a 'whales' eye.
Swell . . .
