Hmm... let's see if I've got this right? An average is now a lowest common denominator. Recognising that the 'folk' are not all academics is 'dumbing down' and, this is the biggie, 'mythical huge readership'? Who said that?
All of this kind of supports my point. I think to call the average person in the UK 'the great unwashed who can't read very well' is a bit strong. The fact is that average means just that and actually a reading age of 12 is pretty good on a scale that only goes up to 15 years!
My brief when I was offered the job was to create a document which would appeal to the widest cross section of the community. I'm sorry it didn't make that transition. Perhaps the readership have more to do with that than they realise?

cheers,
Paul