I don't understand the problem either. I either don't read them or just hide them. The nice thing is that then you get to see the threads that have just slipped off the bottom of the "Active" list as they move up to fill the gap.
Sometimes I might even join in with a game, but I get frustrated when someone has misunderstood the game and throws the thread off kilter.
The games DO have their own section. You can't set GN to hide all threads in one section, but, as has been said, we've asked for lots of things and have resigned ourselves to the fact that we're never going to get them.
And there are always those who start a thread in the wrong section. Either by mistake or because they are new and haven't figured it out yet.