No surprise there. CSEB is an entirely different material from regular old compressed earth block, which itself is entirely different from uncompressed earth. Squeezing out the empty space and adding a binder (cement) makes it all one solid piece as strong as concrete. Uncompressed earth is just... dirt.

It's like saying, "Concrete roads won't work. How do we know? Because gravel is an ingredient of concrete, and gravel roads suck."