IIRC, if the cabin pressure was kept at 8000ft until actual height above touchdown of 10,000ft and the aircraft then descended at 2000/3000 feet per minute, your poor old eustachian tubes would be subjected to a high rate of pressure increase and would lock up. With a heavy cold, it could be difficult or impossible to clear them with the
Valsalva manoeuvre
For that reason, reduction in cabin altitude is spread over all of the descent limited, as implied by QA1, by the design operating differential pressure.
This gives the cabin a much lower RoD than the aircraft.
Interesting useless piece of information is that, since the diff press in the cruise is about 8psi, if you look at the size of the doors you can calculate the outward force on them; it is surprisingly large.