It's a bit purple, but it reads fairly cogently to me; it's just a very long run-on sentence.
That might be attributable to dementia, or a deliberate style choice; I'd kind of lean towards the latter given that plenty of the preceding article is expressed in clipped, curt statements without much excessive detail.
It is sad, though. The writing of Terry Pratchett puts this on somewhat depressing display, with many of his later novels lacking the punchy dialogue and tight focus of his early and mid-career works. They feel a bit more floaty, out-of-focus, and characters are more likely to pontificate than demonstrate a point through action or indirect reference.
They're still good stories written by a very talented and creative author, but you can tell that he was having more difficulty with it towards the end.
Similar to Pratchett's later books -- and Iris Murdoch, as mentioned in another comment -- are the late works of the composer Iannis Xenakis. As long as a decade before he was forced to withdraw from public due to dementia, his music underwent a very peculiar stylistic change where the immense complexity of the earlier pieces (Xenakis built his career on combining music with his work as a modernist architect and erstwhile student of maths) gave way to a very repetitive, single-minded sort of texture.
That might be attributable to dementia, or a deliberate style choice; I'd kind of lean towards the latter given that plenty of the preceding article is expressed in clipped, curt statements without much excessive detail.
It is sad, though. The writing of Terry Pratchett puts this on somewhat depressing display, with many of his later novels lacking the punchy dialogue and tight focus of his early and mid-career works. They feel a bit more floaty, out-of-focus, and characters are more likely to pontificate than demonstrate a point through action or indirect reference.
They're still good stories written by a very talented and creative author, but you can tell that he was having more difficulty with it towards the end.