This is exactly correct, and electrical code still requires the "faces" to be upside-down if the electrical box has a metal faceplate, which is still common in

This is exactly correct, and electrical code still requires the "faces" to be upside-down if the electrical box has a metal faceplate, which is still common in many industrial settings and also house basements. If the faceplate is plastic, it doesn't matter. Also, in many houses you'll see the outlets oriented both ways in living and bedrooms, and there's a reason for this: what you'll see is all the outlets oriented one way (usually with the "face" right-side up), except for one outlet, which is upside-down. That outlet is the one that's controlled by a wall switch, so you're supposed to plug a floor lamp into it, which can then be switched on with the wall switch when you enter the room. Inverting that one outlet makes it much easier to see which outlet you're supposed to use.