You know what rich and powerful people want? More money and more power. I hope in my lifetime I'll see a leader of this nation who isn't fueled by greed.
George Washington would be the closest person/president this country has seen in that office to the fitting of that bill, and he was a rather rich Virginia slave holding landowner (though albeit mostly thanks to Martha) but he sacrificed, earned, and laid it all out for the ideals he was fighting for and wasn't driven at all by greed to be president, but rather "hey you are like the most qualified person just take it". He served out of duty, especially his second term, and quit out of a sense of duty to the ideals of the republic after that second term. Very few presidents can stake a claim that close.
Everyone who seriously aspires to be president, even if they are poor or from lowly origins are in general by nature greedy. You have to be ambitious, and greed often fuels that ambition. Also, this can be said about nearly any leader from any country and any period of time where it wasn't some sort of birth right claim to being the head of state. You want some non-greedy head of state? Make it hereditary or draw from a giant lottery pot. That's about it.