2007 was offically the beginning of the end.

Before that gaming was still popular, but it still kept its "enthusiast" vibe, if you liked video games you were probably a nerd or a bit fringe, and the games reflected that with more creativity and unique ideas. With 2007 gaming had offically exploded into the mainstream with Halo 3, Call of Duty 4, Guitar Hero, Wii Sports etc; these games weren't just popular, they were mainstream culture, and like with anything that enters mainstream culture, it rapidly begins to turn to shit