I do a lot of traveling, and it has always bugged me why do hotel beds sit so high above the floor? You might say it facilitates vacuuming under the bed. However, a large majority of beds are not resting on a bedframe. Rather, they rest on a solid support known as a shadowbox.
The only other WAG I can make is that this is done for the ergonomic comfort of the housekeeping staff who must bend over the beds all day long, freshing room after room. Maybe that’s the reason?