Probably because most people lack the imagination to prove that they deserve what they have or get, someone invented criteria that are supposed to stay in the human minds and feel very comfortable there. Some of these are financial status, the noble roots and the social class you were born in as well as others… The number of these ideas is not the point of this essay but the use of them is.
For centuries people have taken advantage of their inherited social status, nepotism and family business being almost the only ways known. Men found in this a salvation from having to prove they were worth it and a reason to think they are much better than whoever, whenever, however not taking into consideration that the class division made everybody believe the same about themselves.
The poor thought they are more human and less selfish, the working class thought that their effort is the one that makes the world spin and the nobles believed that they were there to lead all that and inherit all that is profitable.
However, respect became an issue when people had to gain it and not impose it through a certain kind of degree and when the family you were born didn’t create your own value. We could say that is one of the good things capitalism did for society: it created competition; a game in which money might still win but if that’s all you’ve got then not even they won’t stay with you for too long.
So nowadays I’d like to believe that other criteria work, some of which are intelligence, creativity and the respect we’re capable of showing towards ourselves and others. Humanity is back to the jungle laws in a new re-edited version, not necessarily milder but more subtle so the saying “Shall the best men win!” is still in use just that the term “best” is a hard subject to define and put a border to.
As a conclusion, elites are an escape for the ones that are lacking the ability to do and think better or…more.