It's not increasingly bizarre, really, if you just allow for the possibility of one thing:
There's something else worse that they know could be in such a book, but isn't yet, and it is so bad that it is worth doing this.
Perhaps they know that Wynn-Williams could have put it in the book and didn't. Perhaps they know that someone else — someone else British, say? — could write such things in a book and so far hasn't.
Once you assume their motivation is grounded in real fear, it gets easier to see why this isn't bizarre at all; it's inevitable.
There's something else worse that they know could be in such a book, but isn't yet, and it is so bad that it is worth doing this.
Perhaps they know that Wynn-Williams could have put it in the book and didn't. Perhaps they know that someone else — someone else British, say? — could write such things in a book and so far hasn't.
Once you assume their motivation is grounded in real fear, it gets easier to see why this isn't bizarre at all; it's inevitable.