After some time watching the tournament play out, I can already agree with people on banning Turf War. It has it's issues from a competitive point of view, but from a spectators point a view, it's even worse.
As a small example, if you watched the Nintendo World Championship when they played Splatoon in Turf War, they had both the monitor AND Gamepad streaming to the big screen. If it weren't for that Gamepad, spectators would just be left frustrated and wondering because they don't know who'd be winning.
Now, look at your average person streaming Splatoon... Do they stream the Gamepad, no. Why? Because it's expensive to have your Gamepad modified to record it and it's not that worth while in the end since most games don't utilize it well. Anyways, when you watch Turf War, it doesn't give you a sense of who's winning or losing because you can't view the map, you only get one player's view, the first 30 to 50 seconds of the match doesn't matter because the whole map isn't covered and you won't know who's in the lead. Now, I know there is an indicator of who's winning or losing the match based on the size of the squids on top, but whenever there's a stalemate / steady ground between the two teams, you still won't know who's in the lead, and even the competitors themselves won't know who's in the lead.
With all this in mind, you can see why spectators and competitors don't like Turf War. Spectators would have a hard time rooting / booing someone when they can't see how much progress is being made, competitors will have a hard time gauging on who's winning during a stalemate, and since it comes down to how much ink you spread, it can leave people feeling cheated in the end result, even if it looks one team was supposed to win over the other.