[gridlock]

"There's no rule against it, so they've made a rule against it."

I don't have the Australian rule-book in front of me, but I would bet you dollars to donuts there is something in there about intentionally distracting your opponent. For instance, you are not allowed to yell when he is trying to serve. I would think this excessive grunting would fall under that rule.

[raybbr]

"There's no rule against it, so they've made a rule against it."

Which, of course, means they just made a rule against it. Rules can be changed to the betterment of a sport. Live with it.