I was suffering from massive cultural shell shock...
I'm going through that now, but apparently, in the opposite direction. I have no problem with diversity--it's the speed and degree of 'erosion' I've seen just in the last 20 years. Doesn't help that I'm pretty socially isolated and when you have no one to talk to during those bleak times, you sink into that 'dark night of the soul.' Maybe it's just late-onset mid-life crisis, but when you said "massive cultural shell-shock," I just think that nailed it right on the head.
I think we have a problem we (writers and the market in general) are not really dealing with. Kids are interested in books with these fantastic elements. Christian fiction is squeezing them out in drips and dribbles. The secular market is putting out these kinds of books at the speed of sound but there seems to be no line they won't cross. Between the two, there's a vast crevasse.
When good overcomes evil in secular fantasy, it's only at the very end, and in the process, they (the writers) have focused entirely on the dark elements and even glorified and glamorized them. A book is not evil because it has a witch in it. It comes down to what that witch does, and when a book has nothing good to express or moral to teach, it doesn't even need a witch in order to do lots and lots of damage.
In my opinion, we pay way too much attention to individual elements and that's why some good books with Christian messages ably expressed don't make it onto the shelves. Bad writing will do that too, but we're shooting ourselves in the foot with that general mentality. A lot of kid's books published in the CBA are stuck in the "Goofus and Gallant" level and though parents may snatch them up, their kids aren't cracking them open to read more than the first page or two.