Thank you for the summary - i do not have a copy of the refs you cite to hand.
Interesting - but I would have a completely different understanding of politicl correctness.
I think there is something in so much unqualified praise for children's work that they fail to develop a discriminatory faciliyt - ir that it undermines the fact that they know that some things they do are better than others (I think that is a pillar of montessori teaching - that teachers do not offere critical feedback of work on the grounds of it being 'good' but allow children to make thier own judgement).
But I would be surprised if this so-called political correctness was really having such an effect on children in the way described. The context of value judgements on one piece of music being better than another, for examplae are strong, the arts are teeming with awards and prizes, from Turner to Booker via the Baftas...until I read the books you refer to i think i will still suspect that consumer desirability is more persuasive in distorting value on aesthetic gorunds than political correctness.