Most factors are outside their control. You don't choose your DNA, you don't choose your parents, you don't choose if you have family members in jail or on drugs, you don't choose how much money you have growing up, you don't choose how much funding your school has, you don't choose whether or not you have family members to support, you don't choose whether you have enough money to go to college.
I never said hard work is a bad thing. I just don't think it has much to do with success. Claiming that success is mostly hard work is nothing more than ********, right-wing, neo-liberal propaganda. Especially when it flies into the face of research that shows that more or less, you're going to end up being the same economic and social class as the one you've grown up in.