Funny that you mention that... lots of game companies are, shall we say, less inclined to include documentation with their games these days. I can name at least 5 games in my collection where the "manual" is less than 10 pages (three of which are published by Activision, no less); and this is excluding all the PC games that forego a paper manual for a PDF file on the disc. Now, I understand that companies have got to look after their profits; but when Nintendo can include a 100-or-so page manual (that serves as a quick guide to the first few hours of gameplay) with Dragon Quest 9, you really have to wonder why other companies put next to no effort in to their own documentation.
Going back to the point where PC games usually just have a PDF manual on disc - I can sympathise with why people would pirate games like that. Why buy it when you can torrent it and get exactly the same product, manual and all? Of course, that could be my own opinion, since I love a good manual, but I'm more inclined to keep hold of a game (rather than just sell it on when I'm done) if the publishers at least gave enough of a damn to include a decent manual.