They highlight bad appliance design especially hard, while also being somewhat difficult to pinpoint due to the design of many electrical systems. Arc detectio

They highlight bad appliance design especially hard, while also being somewhat difficult to pinpoint due to the design of many electrical systems. Arc detection is also basically somewhat complex RF processing, so there are multiple approaches to it and implementations vary. Plus (detected) arcs are common with for example brushed motors. Maybe there's something else the person you replied to would like to highlight, but I wouldn't call them a money grab, just made difficult due to some past choices.