It has close to nothing to do with housing or camping/resting.
Except the very essence of that
Sleep safely within the keep, though potential quest related enemies such as Degardan of Edwin’s quest can still find you there
Really ? The very essence ?
Did you travel there only once to sleep safely ?
Answer : no.
Being able to sleep safely doesn't mean that it was one of their appeal / their goal. That's exactly why I wrote "close to nothing"
