While a lot of people play God of War for it's best in the genre gameplay, more people play for the story and characters. I love everything about God of War equally, the visuals, gameplay, story and sound are all top notch which is why the games totally own the genre in everyway by such a massive margin.
Do you really think God of War could have amassed a dedicated fan group this big: https://www.facebook.com/godofwar.page?fref=ts if it were just great hacking and slashing game with no purpose to play, I doubt it. People love Kratos, people love Greek Mythology and they love the twists Sony Santa Monica imposed onto it. The story is what makes millions of people want to keep playing through the games whilst the gameplay keeps them addicted.
And for a franchise that you think nobody should or does care for its story, it sure did well in this competition http://www.g4tv.com/vgdm/best-video-game-story-2012/, 2nd place only to Mass Effect.







