I was under the impression that objects inside a cabin decay at a slower rate but they still do decay. Objects inside a cellar, however, do not.
If no one can confirm this specific occurrence inside a cellar then it would appear that it is all the same bug: broken beds become unusable and unfixable due to their lack of a bounding box once they've been slept in. (I just checked and the beds I have in the cellar work as intended.)
The reason the bounding box is removed is so that the player cannot get stuck in their own bed when logging in after sleeping in it, the same way you can pass through your own Hearth fire.
It seems to me that the easiest way to fix this problem would be to use the same code that quicktravel uses when porting to a crossroads or village idol: log the player into a random open tile near the bed.
In fact, the login procedure should function this way all the time. If the player's login point is obstructed, the game should attempt to place them nearby rather than prohibiting them from logging into their last location.
Edit: This seems to be relative to my earlier post:
http://www.havenandhearth.com/forum/viewtopic.php?f=4&t=2928If my hypothesis is correct, that is that for whatever reason the recently high rate of server crashes has been accelerating the decay rate, then it makes sense that all of these beds would be breaking right now, bringing this bug to the light.