To change that is base on the topic at hand. People discuss what concerned them. If you are interested to discuss Man United and Man City, you can initiate the discussion and others will follow. In the weekend there are a lot of games to discuss here. And anyone can bring my of the games and create a discussion here.
On Saturday 13 September 12:30 Arsenal vs Nottingham Forest, and other 7 games on that the same day. And Sunday 14 September, Liverpool vs Burnley which will be a auto win for Liverpool and for the game between Manchester United and Manchester City, as for me it will be clear win for Manchester City.
If I missed understood you, you can correct me.
I really don't understand why his sounding that way, like you said earlier, people discuss what concerns them, he can start a conversation and if people feel like keeping up with it then they can simply key into it. There's no need of him trying to make people talk about something else, besides the Manchester derby discussion is also been talked about here in this thread as well.