It's not so much that they 'couldn't say why' as that they don't care to repeat themselves. The KLF have explained themselves at great length in their own publications, which I heartily recommend: http://klf.de/home/publication/manual-number-one-easy-way/
The Manual has been floating around online for ages! I got annoyed with the typos and OCR issues, so I cleaned it up a bit: https://github.com/pronoiac/the-manual
