I believe dumbed down instruction is one of the major misconception of teaching.
One of the success factor of the "Harry Potter" series is the J K Rowling do NOT dumbed down the language. She writes for an intelligent reader. Children love it!
Scarfolding provides support for intelligent and capable learners who are new to a discipline. Dumbed down implies the learner is lesser in ability. Scarfolding is not "dumbed down".
Stephen Downes wrote
as the (adult) readers alternate between being impressed by the review and not believing that a 12-year old wrote it.
This shows that a lot of people think that children are of a lesser ability - which, as Stephen correctly pointed out, is unjustified. "It's worth remarking (again) that children today spend their days reading and writing on the internet. So a literate review from a 12-year old should not be a surprise."