I just don't see where Call of Duty can be considered overrated. It's one of those things that makes a lot of money, but everyone knows it's just not very good. Like Twilight.
The shooter gameplay for Infinite feel almost identical to the last two games, so I'm not sure how you think they're any different, let alone better. Unless you're talking about the rail/tear aspect to the game. Which is very cool, but you don't see enough of the former, and the latter is just a fancy way of spawning items and cover.
I agree the story is really interesting and cool. It's got a few holes in its reasoning, but it doesn't keep it from being one of the more original stories in quite some time. Game or not.