This is patently absurd. Waving a weapon around in a threatening manner isn’t the same as firing it.
Having expended ammo well into the five figures on the Army’s dime, I can assure you that, either in a static or mobile configuration, you won’t hit anything but dirt if it’s more than several meters away. Every now and then we would try this, just for fun, going through a few transition or handgun drills gangster style. (In the same way we’d go full auto from the hip if we had to burn some ammo before going home)
I can’t imagine pointing a sidearm sideways unless they were trying to be menacing. Against an armed opponent it would be suicide.
Precisely why it is laudable for potential opponents to use this technique. If someone is threatening me with a gun, I *want* them to use this technique!
The technique was quite common during the 1920s, 30s and early 40s in pre-revolutionary China, when a jolly mix of bandit gangs, Nationalist and Communist armies, and localized warlords all fielded armed troops- as did the Shanghai police force and the U.S. Marine forces of the Fourth Marine Regiment and embassy security detachments.
Popular in that time and place were the full-auto versions of the Mauser M1932 *broomhandle* pistol. Which, if fired without the shoulder stock attached, did tend to rise nearly uncontrolably. Unless, of course, you turned it on its side and let it walk across a line of targets.
A fella armed with a full-chat broomie with a 20-round magazine is not at all poorly equipped. And using one in such a fashion is far from suicidal.