My wording was unclear - my mate was horrified that the film stripped the book of the Gray-ian Glaswegian elements and plunked it iin a twee, whimsical steampunk-eqsue world.
TBH, I can't remember much about the book, it as a while ago. In terms of being horrified by books by Scottish Authors, I'll point you in the direction of Iain Bank's Wasp Factory and Complicity as ones which I've struggled with because of the violence.
Ah, I see. I can understand why that might be horrifying. On the other hand, a book is one thing and a film another. And sometimes (not saying this time) the film is better than the book. Any film based on the writing of Dan Brown springs to mind. I try not to think of a film as being the book in another form, but it is difficult, and annoying sometimes.