I call them casual gamers. They're not really interested in the breath of games the industry has to offer & their consumption habits are very limited (casual consumers?).
I'm sure there's a better term but this is what I use. To clarify I think this actually represents a large portion of gamers and I don't see it as a bad thing, but its in stark contrast to audience that is avidly watching E3 for the next game they're going to get excited about, or the kind who picks up a title because its on sales or because they've heard good word of mouth, the kind who is frequently navigating reviews and gaming media to find their next purchase. New games and Ips often rely on this latter audience to gain some traction and footing.
In the mobile market there is a term called "Wales" but thats for people who spend a large amount of microtransactions on one game. I think the same can apply to many FTP games on PC or console.
