Communication!
Imagine for one second refs being mic'd up and the crowd being able to hear communications with the players/VAR. Not only does it make everything 100% clear hell it even stops players talking to them like shit and introduces a much needed bit of respect into the game.
Nothing to fear, nothing to dislike and nothing to lose but nope..........not happening.........ever with this lot we currently have running the game, hell, they wont even allow its usage as per UEFA's own guidelines as thats a bit too honest for them and puts the onus and responsibility on the man in the middle having to look at a screen and holding his hands up to either being shit and blind or just fucking bent.
Nah.....keep it secret, play with your ear for 5 mins and then go with whatever suits the game/teams/players/managers involved and i wont even say agents, bookies and brown envelopes.