Identify your golden egg laying hen

What is the reason for an employee to leave some company and look for the better opportunity? Why an employee want to leave its current company. In my opinion, its company's fault for not providing what the employee wants.

Actually we need a system where somehow the system should able to tell what the employee is actually looking for. I know now you will say that it is impractical thing. A CEO can't go to every person and ask for what he/she is seeking. But that's what for your top management is. Every organization knows that no employee is same. Everyone has their own talent, thinking and life perspective. Yes, I am saying that you need to identify your employees.

Consider this analogy; you have a farm in which there are thousand hens. Each hen lays 1 egg every day and you earn some credits by selling it. One day while selling you found that one egg is golden and you earned some extra credit. Now you know that one hen in the thousand is giving golden egg. You can stop reading further if you are satisfied with your current credits and don't want to find out who has laid this golden egg. But if you have big goals and dreams I guess you would like to find out that hen who has laid this golden egg. But the most important part is that the hen who is giving the golden egg is doing the hard work to find golden worms to eat. Some of your employees will be like that hen only. I know most of the company's focus on work life balance. But I want to tell you that there are some people who are ready to sacrifice their enjoyment and social life because they want to do something big. They had already made their choice. I guess a successful CEO of any company knows what it takes to achieve big dreams. So, if you fail to provide it then you might give birth to your rival.