There's only so much you can say to any group of players before they stop listening.
I've still got a scrapbook at home of the Munich air crash. I was an Arsenal supporter, and I went with my dad every week. I would have been 11 in 1958 and remember standing at Highbury for the Busby Babes. I remember that was the last game before they jetted off to Europe, and a lot of them never came back.
I see it every week - parents shouting and screaming at kids. My dad was the same. He was always there, but he never interfered. Ron Greenwood, who was the manager of West Ham when I was a kid, wouldn't allow any parent to shout from the touchline. He thought players should be allowed to think for themselves.
When I was a player, you only left the club if they wanted to get rid of you. That was your team - if you were at West Ham, you didn't leave until the manager wanted to replace you. You didn't think about playing for Arsenal or Chelsea.