Why did the Front Man join the organization?

In the penultimate episode, it is revealed that

Hwang Jun-ho's brother

is the Front Man, the leader of the game. He becomes so dedicated to the game, in fact, that he is willing to kill the aforementioned character with nary a flicker of hesitation.

He would have many reasons not to join: after all, he won the game, so he would have been given more than enough money to survive (although he could possibly have spent it all). Furthermore, the game organizers would have put him through a number of lethal competitions, giving him more reason to dislike them.

It is true that a potential hint is given when he kills a corrupt guard, saying that the game is pure because everyone competes under equality of circumstances. However, it is hard to say how disingenous this statement may have been: the players are manifestly not equal in their chances of winning, since the organizers give them games where certain individuals could have a clear advantage, such as tug-of-war or impromptu battles royale (not to mention the first game, where faster individuals and individuals with good self-control had an enormous advantage), nor are they exempt from interference by the organizers, as we see, for instance, when the Front Man manipulates the penultimate game in real time.

So then, why did the Front Man join the game and become the practical leader of an organization that he had every reason to loathe?