It's because of the concept of successful ambition correlating with the lack of morals or integrity. It just so happens that people ambitious enough to do whatever it takes to rise through the ranks often have to be necessarily immoral to step on people to get to the top.

People who have others' best interests at heart simply don't take advantage of the opportunities as often because a number of those opportunities would involve unfairly stepping on someone else.

So to answer your question, yes, ambitious assholes tend to ride faster and further than good people. Kind of like how a large portion of cops tend to be former bullies.