I wonder if there are regulatory reasons that prevent IEC connectors being used in e.g. washing machines. I guess getting a water ingress protection IP rating might be harder if you have an IEC connector. The lack of an IP rating might prevent you from then installing the appliance in, say, a bathroom (depends presumably on country-specific regulation). This in turn might limit your sales.

Even if that's the case, the appliances should be easy to repair for a competent person and if necessary allow the cable be replaced.