That makes so much sense. It's tricky with beloved children's texts. A child is unlikely to notice any of the problems. When that now-grown child reader is confronted as an adult with the text's occasional ickyness, I think many people react either with denial ("why are you overreading it! It's just a children's book!"), or fury ("you have betrayed me with your secret theism, CS Lewis! I am going to write my own trilogy in which I kill God, just to show you how much you suck! Nyeah!"). When the reality is the books are likely to be a mixture of good and bad, subversive and hegemonic, complicated and oversimplified, just like everything else in the world.

I see what you are saying about class and the Calormen, and I find it fascinating. On the other hand, the question of race is a more complicated one. I don't think it's racist to say "that particular culture has bad values", but I do think it's racist to construct a culture of a different race in the fiction and give them only stereotyped negative values. (And stereotyped positive values: they value storytelling, as long as they are elaborate stories.)