As for the FIFA, as a spectator I find it highly annoying if a goal is rejected if the ball clearly went in, especially because all the cameras prove the opposite, or if a player is sent off because his opponent felt the need to dive, no matter who they are or what clubs they plays for. And on the screens in the stadiums such replays are rejected by the FIFA regulations too, trying to hide the fact of the goal for pretty much no reason (in other words, they know they are wrong but don't dare to admit it).
Just think of the hundreds and thousands of people it upsets. A continuous camera referee would solve so much frustration and anger, and would make the game so much more enjoyable in a positive way.