Why is it football teams never play the superbowl at home but in hockey, the Stanley cup is played at home?

If there is a super bowl in football, each team plays away at a random stadium but however, if it is a Stanley cup game, one hockey team is playing at home so in other words, a hockey team will be able to win a Stanley cup game at home or the final Stanley cup game? In football, no team can win the super bowl at home though. Why is that?