t the controls for dishwashers are becoming more and more electronic and le ss and less mechanical. The electronic components insulating ability break s down over time and current can leak to the metal frame thereby creating a shock hazard.
It's not much of a shock hazard if the metal frame is grounded, which has b een a code requirement for a very long time. The poster raises a good question . It would be interesting to see if they have any real world data that justif ies making this GFCI or if they have no data to back it up.