When the optimal strategy of tick-tack-toe is known to the players, the zero-sum game is fair and it ends in a tie. So this game can only be fun to players who do not know the optimal strategy. In chess, many players still do not possess knowledge of its optimal strategy. And for this reason, chess remains enjoyable. More about game theory see the website at http://en.wikipedia.org/wiki/Game_theory
in the search for a TOE, can this search be considered as a game? So this search can be fun only if the optimal strategy is not known. whoever found it first wins. But searching for a TOE is a nonzero sum game where, in the end, everybody wins even if only one person found it. So there is no reason why someone who already found it would keep it a secret from the rest of the world.
But one bothersome thought is whether finding a TOE can be used as a weapon for destruction of life (as what was witnessed by the nuclear age in the early 1940s)?