I've not read IT. The only King novel I ever read was Carrie.
But can't think you know an author by his fiction. Fiction might reveal something about an authors' inner fantasies, or not.
Fiction might reveal something about an authors’ inner fantasies,
..or not..
/
or does.
It was revolting.
That ending added nothing to the story line.
It was not only devoid of all redeeming value, it was in no way entertaining or satisfying .
Fiction is supposed to be enjoyable.
It was like sitting in your favorite restaurant , for hours, only to fed a plate of salmonella.
There was no reason for it.
So I conclude it DOES reflect his inner fantasy.
I could be wrong, but it still marks him as one no decent person would want to associate with, to even think of that ending much less use it.
Up to that point I had read all his prior books, even the ridiculously long unabridged version of The Stand.
But that ending of IT was like living with someone you thought was an okay dude , only to find he had the mind where only a chomo would could relate to .
I think he wrote it to push acceptance and normalization of pedophilia .
Much like academia is doing with all the sick curriculum parents are fighting to get out of our grade schools. And also the lbgbt+P crowd.
Ymmv
You can give him the benefit of the doubt if you wish.
.