This is address to the general conversation but to no specific poster individually:
Do you understand what you are asking of 18-21 year old young men when you say that to be a good football player they have to be able to totally ignore the bad behavior of some vocal minority of the fan base? Remember, we aren't talking about one loan voice on a message board, we are talking of the propensity for group-think and for a small minority of people to be very angry and vocal about their disapproval.
First, you are basically asking for young men to exhibit sociopathic behavior, which can be the inability to empathize and to ignore the expectations, criticisms, and even affection of those around them. It is far more terrifying to me to think of people who are truly able to wade through the funk of irrational fans and not be affected than it is to find a young man who is affected, even on a tiny level, by the crazy stuff that fans say. In fact, I think you would find that it is healthier for people to be affected on some level by other people's bad behavior than it is for them to be capable of totally blocking it all out without exception.
Second, if you believe that athletes should be unaffected by the fans, then why do you go to a game, scream, yell, cry, boo, and develop any emotional reaction at all to a sports team? If you have ever been upset after a loss, or yelled until you are hoarse, or worn a special t-shirt or hat on game day because its "good luck" you are in fact allowing emotion to control, even override, your behavior (especially if you believe that the athletes aren't or shouldn't be impacted by fan behavior). Who here hasn't had performance on some level affected by emotion? Have you ever been depressed or angry after a loss of a football team that you don't play on? Have you ever had an angry reaction to another fan who disparages your team, perhaps to the point of physically fighting? If so, you are allowing emotion, and feelings, affect how you interact with your own world, and sometimes in a way that negatively impacts your abilities. I don't know anyone who at one point or time or another hasn't been driven to a foolish act that they regret due to being emotionally hurt by the words or actions of someone else. Ultimately we all discuss how we want players to play with emotion and heart, yet we are then making an argument that players should be immune to emotion? Odd.
Third, for those who believe that there is no cause and effect relationship between fan negatively and recruiting or other aspects of play, because the damage isn't massive and immediate, you are ignoring the impact of small damage over long periods of time. It is almost like you are saying that smoking isn't dangerous because one cigarette never killed anyone...in fact, I know smokers who were very active and healthy...until they died of lung cancer. Not all smokers die of lung cancer, but the connection is there over a long enough time period it becomes irreversible. Why risk it, if you truly value health? Ultimately the justification for smokers and for fans who believe they have an unbridled right to say whatever they want is the same...because it feels good, and/or because everyone else is doing it so it can't be bad.
I am positive that most people are already set in a position, and that this falls on deaf ears. All I can say is that I believe it better to be a lone voice, if the call is to reason, than to be just another man holding a pitch fork.