I have a slightly different outlook based on experience...
VAG's engineers design things so they're easily assembled on the production line with little, if any, thought given to servicing & repair later in life (example, control arm bolts, that stupid plastic oil cooler pipe, the Passat W8 where you have to remove the engine to change the alternator, etc etc etc). The complete dash assembly with heater, wiring harness, ducting, reinforcement bar, etc is installed as a single unit on the production line so all the gubbins inside it is assembled outside the car. There is no thought given at all to taking the shell out on its own (example the B5/C5 climate control sensor wire I mentioned earlier).
It was designed to be easy to build, not to be removable later
