I've seen kids get smacked or down right yelled during a baseball practice of game, for merely throwing the ball a little to the left or right of the first baseman, or not making it to first 1.2 seconds prior to runner getting there.  These kids are 5 and 6.  To me, that is wrong.
Sure I have yelled to DS6 to throw the ball TO the first baseman (actually he plays first, but still).  Or I have "yelled" to him to get back in his stance when he's up to bat.  But I would never consider smackin' him upside the head or making him do laps because he missed a ball during a game or sit there and tell him he'll never amount to anything, etc, for him not being an MLB caliber player at 6 years old...  It happens; I see it all the time.  And it's sad to me.