Except baseball is not physical. I only condone this kind of behavior if, in a physical interaction, there is something done wrong. Like steamrolling a catcher, spiking a 2B, throwing something at someone, etc. But these are exceedingly rare. Otherwise the behavior just remains stupid. The unwritten rules are (and you see this in the player comments in Kurkjian's piece) designed to ADD physicality to a game without any. Basically, they exist to allow baseball players to be violent when they otherwise would have no reason to be. Violence is inherent in football and hockey, it has to be concocted by macho softies to exist in baseball. So it doesn't get to escape the loop of stupidity it is founded on. If you want more proof of that - go read everything Johnny Gomes says in the Kurkjian article in defense of them.