I think we’re really talking about reading intent. And the object of the anger can do that, whether a child or a high school or college football player.
There’s a major difference between (1) giving a 10-year-old a deserved swat on the butt cheeks and (2) punching his lights out. There’s a difference between holding a player accountable and devolving into personal denigration.
I have no problem with delivering a message with a greatly raised voice, even if it contains a lot of profanity. I have a major problem with aiming the profanity at the player personally.
”You’re playing like )(*^)(*&….we’ve taught you way better than that and you’re disrespecting me, your position coach and all your teammates when you give that kind of (*)*^&& effort. Your choice: You will get with the ^%$%(*&^ program. You will (*&)*& practice with focus and &^%$*%^ effort. If you don’t want to do that, not a ()*&)(*& problem in the world….we’ll )(*^*&^&. fix it so you hever have to set foot on this *)&%(&%^ field ever again.” No problem whatsoever. Even if the message is delivered in the loudest voice the coach can muster.
”You’re a (*&)(*&^& and I’m #^%&*&^*&^ finished with your sorry(*)&*^. You’re not fit to lick my (*)&^^ shoes. Get your )(*^*&%%)*&% out of here and go hang with all your other (&^*&^* buddies.” That’s unacceptable, even if it’s delivered in a Mr. Rogers voice.
It’s also counter-productive. People of whatever age don’t respond well to personal insults. They respond greatly when they’re called on behavior that they know is disappointing to someone they also know cares about them deeply.
Children might not be able to articulate it, but they know when they deserve punishment. They also know when a parent crosses the line and a spank becomes no-foolin’ abuse, or when the punishment is disproportionate to the offense.
Football players are no different, except they are old enough to express the distinction verbally. They know when the coach is trying to get maximum effort out of them. They also know when the coach is being sadistic because he can be.
I’ve seen examples of both types of coaching / parenting, and you know the results by the way the people relate to the coach or parent after they’re no longer under that authority figure’s control.
Late Note: I know there are some people who, no matter how much you care, and no matter how much you try to work with them, using any method you can, will not respond positively to anything. Not love, not tough love, not profanity, not Bible language, not begging and pleading, and not a boot in the hindquarters (figurative or literal).
Absolutely nothing gets through to these guys.
Fortunately, there aren't many, and they're not indicative of the vast majority of people. You just have to deal with them on a one-off basis, sometimes to the point of separating from them when you've exhausted all alternatives.
This is especially true in a team context where you have to worry about an entire organization. The organizational leader simply can't allow a bunch of members, who are all trying to do the right thing, to be dragged down by one individual who has made a clear and unshakable choice not to buy into the collective good.