The latest iteration of GH proves this and has done Activision very well. In the first week of sales, they are citing figures as high as $115 Million, making it Activision and RedOctane's most successful title at launch. In a recent interview, the head of publishing for RedOctane, Dusty Welch, spoke to CNET regarding the series and why it had done so well.
It sheds some light on the reasoning they even choose such a genre, which was largely influenced by television. He cites parallels to Nintendo, and how they have been actively seeking to break out of traditional gameplay elements to entice people, if not by novelty than by uniqueness. It's definitely worth a read if you want some insight as to how it came to be and where they plan to go from here.