pvt. AllenDefeate's the purpose of grenades?! Say what?! Grenades are weapons, they are intended to kill not scare away. It is realistic and important for tactics to be able to cook up grenade before thorwing it.
You're absolutely right, it's more realistic. However, IMHO this is a case of "realism" vs. "gameplay". I assume you've played vanilla BF1942, and experienced a true 'nade spam storm from some moron (like me) hanging out at an ammo box, and know how badly that can ruin a map.