Seems to be an informed opinion?

I find the book interesting because we're so used to the CD way of No Dig (hate that expression - its like saying a diet is "No Eat".......but I digress as usual). S-Cs is a book of its time - using peat for example. IIRC he advocates a 1" layer of mulch to cover the bed at the outset - and that's it - not annual topping up with 2".
He also mentions digging out perennial weeds to prepare the ground and there's a bit about rotovating. Its a while since I've read it so don't remember all the detail. You'll have to read it yourself.