Actually, this is one of the things I like (the standing and firing) as it's a borrowed concept from one of the best westerns of all time, "Unforgiven". The idea that it's not who's the fastest to draw, or who shoots from the hip the most times, or even distance or (natural) accuracy; it's all about remaining calm, cool and completely cold-blooded as you stand, aim, and fire at each target in succession.
As has been shown on Mythbusters, a single, well-placed, shot is far more effective and deadly than a spray of bullets. And there is one scene in Unforgiven where he proves the concept and shoots a half dozen men in close quarters; he's as cool as a cucumber and just deals out carnage whilst everyone else is panicking and spraying bullets everywhere but at their intended target.
