I think that it is true that rank doesn't necessarily translate into ability but I believe that rank is useful in that it speaks of the amount of time, commitment, and responsibilty that one has to the art that he or she practices. If we meet a high ranking person that does not exemplify that commitment or who is failing in their responsibilities, that serves to clearly tell us something that we desperately need to know about them. If we meet a person with rank that is outstanding in every regard, that should serve to inspire us to follow their example in our own conduct.
In a heirarchical system, any form of title, honor, or designation which speaks of promotion or increase in authority truly only increases our responsibility and servanthood to that pursuit. The responsibility and service that it calls for will always outweigh any privilege that it bestows. People who abuse the position always mark themselves to be known for what they are. Rank then, becomes a big sign around their neck that says, "I am not worthy". The effect that rank has on us can be more telling than not.