Why isn't Zac disabled in pro-play?

Zac is probably the most broken champion that has graced the rift in recent times, yet Riot has done very little to change this. His ganking potential is through the roof, and he is very forgiving if you can't land your skillshots. He is practically perma-banned in pro-play, and when he does make it through he has no problem single handedly carrying the team to victory.

I'm genuinely wondering why Riot doesn't disable him in pro play (LCS) until they fix him. Red side is heavily handicapped by the fact they have to ban Zac almost permanently, putting them at a great disadvantage. Disabling him frees up a ban slot, leaving red side with more options, and therefore slightly reduces this disadvantage.

I'm sure Riot is well aware of the massive problem that Zac currently is. Making such a broken champion in the first place, that happens. Fixing him? That will take time, especially as the problems lie in his ability mechanics, and therefore may need a new rework. However disabling him can pretty much be done with the press of a button. If Zac does make it through, he pretty much sucks all the fun out of the game with how strong he is compared to other champions.

What are Riot's thoughts on this matter? Because I never hear them talk about the state of balancing broken champions.