Why have no NFL football teams have a home game in the superball?
Because the team that owns the stadium the game is scheduled to
be held in has never won its conference championship. There's no
rule against it, tho. In 2016, the Super Bowl will be held in San
Francisco at the stadium they are about to start building. If the
49ers are NFC conference champions that year - possible; the 49ers
are a good team - they will play the Super Bowl in their own
stadium. (The same thing can be said about next year if the Arizona
Cardinals play their way into the game, which will be held in
Phoenix, or in 2017, if the Houston Texans play their way into the
game that will be held in Houston.)