Well, not entirely. "Adult" as a form of praise is perfectly reasonable, but then, so is "for children" or any other formulation that targets a segment of the market.
To give you the exact words of his assertion--which, I will note, is him responding very specifically to people who were saying that literature written for children was, necessarily, inferior to literature written for adults--here is the full context of the relevant quote from
On Three Ways of Writing for Children, emphasis in original:
This canon [that if a story is written for children and can only be enjoyed by children, it is a bad story,] seems to me most obviously true of that particular type of children’s story which is dearest to my own taste, the fantasy or fairy tale. Now the modern critical world uses ‘adult’ as a term of approval. It is hostile to what it calls ‘nostalgia’ and contemptuous of what it calls ‘Peter Pantheism’. Hence a man who admits that dwarfs and giants and talking beasts and witches are still dear to him in his fifty-third year is now less likely to be praised for his perennial youth than scorned and pitied for arrested development. If I spend some little time defending myself against these charges, this is not so much because it matters greatly whether I am scorned and pitied as because the defense is germane to my whole view of the fairy tale and even of literature in general. My defense consists of three propositions.
1. I reply with a tu quoque. Critics who treat adult as a term of approval, instead of as a merely descriptive term, cannot be adult themselves. To be concerned about being grown up, to admire the grown up because it is grown up, to blush at the suspicion of being childish; these things are the marks of childhood and adolescence. And in childhood and adolescence they are, in moderation, healthy symptoms. Young things ought to want to grow. But to carry on into middle life or even into early manhood this concern about being adult is a mark of really arrested development. When I was ten, I read fairy tales in secret and would have been ashamed if I had been found doing so. Now that I am fifty I read them openly. When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up.
Note, here, that he separates "adult" as a term of
approval (as in, "this fiction novel is
superior because it is adult, rather than being merely for children") from its use as a purely
descriptive term ("this adult fiction novel describes the life of...[etc.]"). You appear to be speaking of it purely in that descriptive sense, with which there is no issue; some fiction is written with children in mind, other fiction is written with adults in mind. Some children may enjoy some literature intended for adults, as I did when I was a kid, and some adults may enjoy literature intended for children, as
we all of us do because D&D is
very literally us writing our own fairy tales together.
Indeed, I suspect, apart from some of the darker aspects that D&D can engender (e.g. greed, murderousness/callousness, tribalism), Lewis would actually have been genuinely delighted by the existence of roleplaying games and their culture of writing one's own fairy-tales with personally-invested characters at the helm. These elevate the fairy-tale fantasy even further. Instead of merely
empathizing or
finding common cause with the heroes of the tale, roleplaying games allow us to
become the heroes of the tale. Instead of merely
witnessing the moral choices of others and learning from them, we get to
make moral choices in a safe, IRL-consequence-free environment. Instead of thinking words of encouragement or kindness for those who are struggling to do the right things for the right reasons, we
ourselves struggle to do them.
To me the two things I've bolded here are one and the same.
I've always maintained that D&D is best designed for and "aimed at" college-age people and above, both in content and in level of writing/prose; and if kids want to play it anyway that's fine too but they're not the intended market.
Defanging it and cleaning it up just makes it boring.
Surely it depends on what one means by "defanging it and cleaning it up." Half-orcs being the product of sexual assault was never positive nor productive, it was just a crappy idea that got retained because MUH TRADISHUNS, and we are all better for its removal.* Drow being
exclusively misandrist, murderous, backstabbing dominatrices
who are the only elf POCs (except the allegedly-few Noble Defectors, like the veritable mountain of Drizzt clones) was not particularly good for the game either, and a better, more
interesting space of stories can be told when this race is more complicated. (It's not like we don't have plenty of enemies literally made of evil and/or madness still.) Failure to include the Realm of the Fae in D&D cosmology was an understandable but persistent error, to the point that even people who otherwise
despise 4e recognize that its addition of the Feywild to the mix was an unequivocal good.
So...frankly most of the "fangs" being removed are ones that were biting where they shouldn't have been, and much of the cleanup has been to produce a game that really does
expand possibilities and the mythic/narrative space, letting us do more, rather than less.
*Especially because it is totally still possible to have "my mixed heritage has mostly been a source of drama in my life"
without any of the horrific-assault aspect. I would know. One of my players, currently on hiatus for health reasons, plays a half-orc who has a troubled family history
with exactly zero assault involved. I was quite pleased with his cleverness on that front and have leaned into the story as a result.