This is the first time I've heard about this but it's pretty interesting. I don't believe that the body is utterly useless after death, simply because from a biblical standpoint the body is not only the vessel of the spirit but the temple of the Lord, so why would the Lord be OK with burning down the temple? Why would Satan have a dispute with Michael over the body of Moses (Jude 9)? And where was Jesus' body after he rose from the dead?
All valid questions that suggest that the Potter will use His clay pots whether it contains water or not. Up until modern times cremation was commonly a pagan practice.
I have never heard of this before and see no problem with it. Your body is a vessel for your spirit. When you die your spirit leaves the body so what happens afterwards shouldn't really matter.
Burying someone is a waste of land and feel strongly that people should be cremated. Everyone has a choice and becoming compost is at least useful. I don't know if I would choose that method though.