I almost feel some sympathy for the welder.
The man only wants to hook up his welding machine, and we present him with an infinite variety of plugs; he doesn't know if he's going to use a dryer plug, or a stove plug, or tie onto a bus bar. It's also unfair to expect him to carry every type of circuit breaker, for every different panel out there! I'm really not surprised to find some very creative wiring on the part of the welding profession!
Apart from crying "egads!," does anyone have any suggestions as to how the code, and manufacturers, can make things safer for the welder? Or, do we expect him to also supply a generator- and use it indoors?