I don't see where anyone is trying to justify anything. You want the air to come out of the vent like a refrigerator. It's not going to happen. That doesn't mean that the system doesn't work the way it was intended. And you don't have to put a clamp on the hose; you are doing it because you want refrigerator air. If like most people you are happy with 40-50 degree temps out of the vent - a number that will go down the longer the system is running - then you don't need to do anything.
Actually there is a "nominal" temperature that has tended to be a standard throughout the automotive industry for many years now. Usually right around 40-42 F at all vents when A/C is on Max, on recirc, running for 30 minutes at idle in 95 F ambient temp with over 50% humidity. This is across all makes and models as well. This is where most folks have a decent level of comfort from the AC system.