since when have any of the greats offspring met or exceeded the parents abilities? why doesn't anyone dump on the Andrettis, Pettys, Unsers (a little different, but still), Rahals, what about Bill Elliots kid? etc. ?
Look at other sports as well, Jordan (his kid was not even a starter at Illinois). I just can't think of too many other pro athletes.
When you live in that shadow it is difficult to have the same drive, and commitment. The greats were good drivers or good athletes, that sacrificed nearly everything to be great or the greatest.