It isn't because of power. If the crew's quarters were decorated with holodeck technology, the hologram would only be generated while the crewman is actually using his quarters.
If the crewman was on duty, asleep, or if the crew went to battle stations, the hologram would be shut down. And this wouldn't result in people living in closets, because while at battlestations, crewmen are at battlestations - not their quarters. A crewman would generally never notice when it is shut down.
The ship's computer had the spare cpu cycles to create and run an entire sentient being in Moriarty. Hundreds of static 'cabins on a beach' quarters are even a drop in the bucket by comparison.
So here is my answer: Holodecks are simply too new.
Holodecks are a relatively new technology. Starfleet simply hasn't had enough time to integrate them into the basic design of a starship.
We don't know exactly when they started to be installed into starships, but we can be fairly certain it was after the between the end of the TOS movies and the start of TNG. That means at some point between 2293 and 2364. I'd be willing to venture that it is far closer to 2364 than 2293.
The system is very much riddled with bugs. In just a couple of years on TNG the holodeck nearly destroyed the ship half a dozen times. That isn't a technology that has seen widespread use for 70+ years. It is possible that the Galaxy class is the first ship to be fitted with the holodeck, at all.
In a modern day military, hulls are designed to last 50+ years. The Excelsior class was in service for over 100 years.
I don't think there would be too much impetus to retrofit older models with holodeck quarters. The main advantages to ship design (making quarters smaller) couldn't really be achieved with a retrofit. What you are proposing would only even be considered after the holodeck is a well proven technology and all the bugs and kinks are worked out.
So perhaps 50 years after holodecks are introduced and they are drawing up plans for a new ship class, they'll throw in holodecks. Unfortunately that time won't be 50-150 years after the end of Voyager.