This front hub visibility thing is a load of old cobblers in determining whether one's bars are at the right distance from the saddle.
There are too many variables that influence the relative positions of saddle, bars and front hub and the viewing angle of the hub:
Neck length
Femur length
Most efficient/comfortable fore-aft position of saddle
Arm length
Head tube angle
Fork rake
Flexibility of back
Limb/torso/neck ratios
As an example, my position is very similar to
Jean-Francois Bernard's - i.e. very stretched out but very stable and comfortable and ideal for both climbing and descending. Although my frame size and stem length are in perfect proportion, my limb/neck/torso ratios mean the bars therefore appear several centimetres in front of the hub, and using a straight edge on this photo you can see that so are J-F B's. Some riders use a far more upright position - it's all dependent on the factors listed above, so there's no point relying on the hidden-hub 'rule'.