What? which drugs did you take?
Lets say, you as a cop are raiding morons, and there's some defense. You roughly know where they are at, and peeking out will result in almost certain death. The only option you have is walbaning. Obviously, if the criminals are shooting they are NOT planning to negotiate about any hostages, and most likely dont have them. and unarmed(haha, lol) would probably yell that they're coming out or something. Why can't you wallbang?
or if someone is behing a barricade, taking cover while shooting trough it. We can't wallbang?
how about this; you're getting bullied but you're not allowed to do anything back because it breaks rule 2.1!!11!1!1!1
obviously, you can wallbang if you know whats behind it.