Actually I would agree that it is close enough for typical sport use. What you are seeing and what is causing the confusion is something that does not show up as easily with balancers that have higher friction and that is a slight off ballance from side to side and not end to end.

Yes even those can be balanced perfectly but it involves removing or adding material to the side of the hub and the process can involve a great deal of time also. Not really neccessary.

John