I think that's pretty much true, except the adventure/visual novel genre. Things like Phoenix Wright and Hotel Dusk are part of a genre that kind of calls for it now and again. It's unfortunate, but it's incredibly difficult to maintain a balance of mystery and clear direction in games like that. Thus, I am more lenient on the need for a guide in that particular genre. Besides, it's usually more than worth it for the story. I used a guide a few times in Phoenix Wright, but it was more than worth it.