Yeah, that's happened before with this game. And actually, it happens to English speakers, too. Compare Planning Ahead (the plot) to Kings of Summer (the agenda). Why does the plot apply to everyone, but the Agenda only applies to the player who controls it?
(There actually is a reason; English has the convention that when a command phrase has no specified subject, the pronoun "you" is assumed to be the subject. But "you" can be singular or plural, depending on the context. For no particularly good or definitive reason within the game, plots are considered to create a plural context by default while agendas are considered to create a singular context.)