So, essentially, you've succeeded in making my shame in never having read anything by him even more profound.

On the other hand, he is simply another name in the long list of great and influential figures who have written stuff that I should have read but have failed to do. 

What did you think of it? Your mate who was horrified by it: did he say why, or do you know why? I haven't really ever been horrified by a book. I started to read Atlas Shrugged but gave up because it's stunningly boring and badly written, full of contrived situations and wooden characters. I suppose I'm horrified that so many people consider it a great work of literature. I didn't enjoy American Psycho much, largely because the author's relish for the pornographic ultra-violence (mainly directed at women) was a bit too apparent. 
 

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.