C/D are more appropriate for industrial use, where wiring and devices are designed beforehand, and people (ideally) won't just join together extension cords, and put multiple electric motors on it.

The fact that they do not leads (non-electrician) me to believe that outlet types differ to prevent unintentionally plugging devices into inappropriate circuits, not to prevent intentional abuse.

The present example is just a band-aid fix for cases where lower-current devices are connected in through some intermediate wiring (UPS, extension cord, RV power system, etc.) with a plug consistent with its own, higher ampacity, and in this application, seems no more prone to abuse than a garden-variety 15 A duplex receptacle on a 15 A circuit.

Those DIYers who reject the “licensed electrician and I need a permit” model could benefit most from them - they’re almost foolproof.

Instead they’re expensive, hard to find as Lowe’s/Home Depot don’t sell them, and not too many average people are familiar with them.

I won’t ever buy plain wire nuts again unless it’s to cap a single wire.