Because you can. Many would ask why you need your room to shake.
Its certainly unconventional, but it must work to some degree or it would not even have been considered for the recording that started this thread.
If it did not work reasonably well, I am willing to bet that both the recording company and the artist would have noticed.
It would be interesting to see how this device measures in conventional sub testing.
Its kinda funny the way we as a species react to the unconventional. I remember this guy by the name of Valekovski who had this theory back in the 40s/50s that mars sent out radio waves. Everybody called him a nut case (and he certainly had some other 'unconventional' beliefs. It took the rest of the world 15 years to catch up with him.
Maybe in 15 years every builder will be putting one of these into new houses.