Basic baseball rules. Seater has every right to get settled in. There is only one decision for the umpire. Just because the pitcher is on the rubber doesn't mean he has to pitch right away. So why would it be any different for the batter?

No dude. There is zero leverage with that argument. Basic rules of baseball. Just because the pitcher is on the rubber doesn't mean he has to pitch right away. So why would it be any different?