I agree with both sides here. You have every right to vent your frustration if you've paid your money and are not happy and it is the only way to directly get across to the players that they have not played to their ability, but come the next game, if the player is of the mentality that if he makes the slightest mistake he will get booed, he will go missing for most of the match. We've seen it with Pistone, Hibbert, Faddy, even Yobo at times.
At the time it may seem like a good idea, but in the long term it will only have a negative affect on the players.
In all professions you will have someone who gets on your back for one reason or another (usually your boss), well imagine 40,000 of them telling you you can't do your job properly and see how you like it. And yes, I know they get paid sh*tloads of money, but no amount of money in the world is going help them mentally, it is confidence that is priceless.