Design rules for appliances are always going to be slightly schizophrenic. They call for both active and return ( or live and neutral) conductors to have equal insulation on them, and that they should both be treated as being live conductors. Then the same regulations say that you should not fuse the neutral, and that there should not be a switch in the neutral side ( double pole switches that are designed to safely switch both conductors are allowed though) in this. Non polarised mains calls for fusing of both active conductors, and for for a switch that is either single pole or double throw. Hard to reconcile them both in a product made for a world market, unless you have 2 versions.
You're mixing up appliances and installations. There is no disconnect in the codes.
For appliances, it makes perfect sense to treat live and neutral the same, as in some areas of the world the plug can be rotated 180 deg without problem, and also, you never know which dork changed the plug at some point.
For installations, it's a different story, as they should be done by professionals, and switching and fusing only the live makes sense to avoid a ton of copper in the house.
I don't think he is confusing appliances and installations.
If the mains plug, is non-polarised then it makes sense to assume that either active conductor is phase.
If there's a polarised mains plug, then it's perfectly reasonable to assume that live and neutral are correctly wired up and the fuse and switch should always be on the phase side. When designing an appliance one must assume the installation is wired correctly and one can't be held liable for a shock/fire due to a faulty installation, i.e. reversed phase and earth conductor. I doubt anyone designing something with a 3 phase + neutral plug, would presume phase and neutral are interchangeable and consider switching two of the phases and the neutral.
In the case of an IEC connector, it's difficult because it depends on where in the world the appliance is designed to be used. You may argue that one should presume that live and neutral should be interchangeable, even if it's designed for use in a location with polarised mains connectors, in case someone takes it to a place with non-polarised connectors, but that may cause it to break some regulations such as fusing the neutral and if you take this stance, then what if the appliance is only rated to 120VAC and taking it to Europe would destroy it?