So, I can see merit to setting a bedroom as a zone, and then placing one more more bed-building designations in there, and you've got a bedroom. Even before the bed's available, thus making the bed an upgrade. Which can be easily upgraded by placing a better bed somewhere else in the zone and then removing the old one (if you aren't making it a dormitory by being multi-bedded permanently).
We can go even farther and have the owner of a room check for him-/herself what furniture is needed and pick it up from a stockpile
This would, however, require Dorfs to to have wants and needs like nobles, though be far less demand-y.
And we'll also run the risk of having a fort full of batman villains, with every Dorf having his/her own little themed lair.