Not sure the electricians comment is related specifically to the three-phase itself, or just to the general observation that three-phase motors are put in more industrial/commercial applications, where reliability is much more important. Pair that with residential use of commercial appliances tends to be very gentle on them (e.g., they don't get run 24/7, vs. a commercial place that would try to use them at every possible moment) and you have a recipe for a very reliable device.