When it comes to focus groups, (in videogames, movies, and all sort of media, really) they guys in charge of them always seem to pick a random assortment of individuals WAY too different from the intended audience, then the project tests poorly, which leads to big changes that alienate its intended audience, rendering the thing a failure, because they were trying to appeal to an audience that doesn't exist.

valve had to remove a lot of shit because their playtesters were practically monkeys with type writers though

not that what they removed was good or what they replaced them with was bad, but listening to everything they said their playtesters did, you can assume they were not the sharpest tools in the shed