Do you boo your waiter if he drops a plate of your food? Z obviously realizes he didn't pitch well, which means booing just boils down to the fans trying to make themselves feel better. No, but in some cases customers might ask to speak with the manager if they are dissatisfied with their food or service. In our case with the Cubs, we can't speak directly to the players or management, so booing is the clearest way to express displeasure. That's where the analogy breaks down. Like I said, everyone realizes that Z/the team isn't doing well in that situation. No one is enlightened by the booing, it's only for the boo-er's benefit.