I'm not at all sure that "everyone" does think that nepotism is universally a bad thing. There is much in what you say; and I make no secret of the fact I once nurtured the hope to be the beneficiary thereof. In the event, I never was, but I remain hugely grateful and hugely conscious of all other things which I have inherited from my forebears. (I'm sure that most members are similarly grateful to their own forebears for gifts handed down, whether tangible or otherwise.)
There is a further discussion (in the Pilotage thread) on the effects of nepotism and the jealousies which it induced; and the fact that it has now been removed with great benefit to pilotage. I cannot imagine that it ever will be or should be re-introduced.