Indeed that's so, but it's not what I said. Those politicians want to dismantle the NHS because they believe that it will inevitably fail regardless of what they do, indeed that it already is failing, and that there's just no way to make that structure work, no more than the USSR could be made to work. That's not the same as wanting it to fail. Clearly life would be easier for them if it weren't the case as then they could avoid being blamed by voters for it.
The book doesn't say they want to replace the NHS with a US style system. Have you read it? I haven't but according to the Guardian - the least friendly and neutral reviewers imaginable - they argue for a French style system instead:
https://www.theguardian.com/politics/2012/aug/22/britannia-u...
Sometimes these are less fearsome than you might expect – Raab likes the French healthcare system; Truss admires the German economy – but often the foreign models cited are Asian
Observe: no mention of the USA. But it seems that the book must hardly mention health, given that healthcare isn't even mentioned on the Wikipedia summary of the book and the Guardian review mentions it only in passing.
The idea that the Tories hate the NHS for ideological reasons and want the US system is a common idea on the British left, but that's not what they really think. What they really think is that the NHS is a lost cause and a European health insurance model would work better. They also think a US style economy would be beneficial. Given that the US is now a lot richer than the UK and their economy is motoring ahead, it seems the book's prediction of a "slide into mediocrity" has come true. The ultimate determinant is wealth - given enough of a gap, a poor Britain will always have worse outcomes than a rich USA regardless of how healthcare costs are paid.