I answered that when I said Bob Glidden was, a) a professional, and more importantly, b) from Indiana - Which happens to be where IRP is located. Thus, the naming of Bob Glidden Drive at IRP. I could add that Glidden is also retired from driving, which is when most - not all, but most - dedications are made, while Manzo is still very much active.
That said, since Manzo is from NJ (where Raceway Park is located) and he's won a lot of races there (I don't know the number, but I know it's a lot) it would seem more appropriate to dedicate that track to him... if one were to dedicate that track to anyone.
If the only statistic for dedicating a track after a driver were wins, it could get monotonous rather quickly. I believe the naming of Bob Glidden Drive had more to do with the fact that Glidden was a successful Hoosier than it had to do with wins only.