I really think that it comes down to a person's genetics determine the characteristics that will define a person's later success. It is quite possible for people to not be attached to their parents and grow up to be successful, but the opposite is also true. A person's relationship with their parents can have an effect on their personality traits, but it doesn't have to. A person whose cares deeply about their parents may want to make money and friends so that they'll make their parents proud, but it is feasible for a person who has had abusive or neglective parents to grow up to be successful for one reason or another. In either case the child must be motivated to be successful, and parents may or may not cause that motivation. It may just be in a person's DNA that they are naturally motivated and so their relationship with their parents won't affect their success.
