You'll be surprised to learn that Anya wouldn't be able to lift the Locust above her head with such ease after a Plancer charge.
Also you can't take 20 bullets from a Lancer, survive, and just stand up a few seconds later.
Also one shot in the torso from a Longshot would probably be enough to kill you.
Weird thing is, because it's a game, there's this thing called gameplay balance. In games these weapons called shotguns are close range weapons, you'll be surprised to find that almost every game makes shotguns close range, because of this thing called gameplay balance.
If you let someone get within ball touching range of you, then you deserve to get blown to pieces because by that stage aiming would be moot anyway, seeing as though you'd probably fill the entire screen and not being able to hit you with bullets would be an achievement.