Read other letters about this article
If the nomination process were perfect then of course it wouldn't be ethical for a group of VIPs to overturn the popular vote.
But, as we've seen, the process practically begs for manipulation by opponents.
The key point here is whether or not the votes are close or not. If one wins by a wide margin then the opponent's manipulation can be safely ignored. But if it's close...
P.S. And yes -- the superdelegates were created essentially as tie-breakers. Their purpose is to vote for the candidate they believe will win the election.