I've brought rope on a few occasions over the past dozen years when I wanted to add a margin of safety to get to someplace I wanted to explore, but even on those occasions I wouldn't really call the situation "dangerous". I just wanted something better to hang on to while I was climbing, but never really needed it. That said, I would not have gone to those places without one, so I guess that still qualifies in a sense, but I'm sure it doesn't rise to the level of what you and W_D are talking about.