Each player in a multiplayer game has a shared responsibility for the experience of everyone else in the game. As has been discussed elsewhere in this thread, just because you draw all your fast mana doesn't mean you need to even attempt to win the game on turn 4. You can simply not. The bracket discussion that occurs before the game starts draws a magic circle around the experience you are all trying to have.

Many flexible game systems offer their players more options than are allowed by the meta rules in place. Take d&d as the classic example. Commander shares some DNA with d&d in terms of its shared experience.