I think this article makes a good point of our debate in the sense that the OP is talking about common situations.
The article states, "because as often as not they’re in a convenient place when the 95 percent/soccer mom crowd needs to be secured to a flatbed, not when the 5 percent/off-roader folks need a yank off a rock."
Taken slightly out of context this makes a very obvious point that this article focuses on EXTREME uses, not your everyday pulling someone out of a ditch, or a snowbank.
Mild carbon steel has a shear stress of around 34,000 psi give or take. A Class IV ball has a 1.25in shank. This means it would take approximately 42,000 lbs to shear the ball, not counting torque/tensile strength, etc. In the case of extreme off roading you also have to worry about loading angle, and your strap/chain/etc slipping off a ball as it is not a closed loop like a D-Ring (advantage see D-Ring lol). In the case of your normal usage crap, a ball is fine, just be smart.