What people don't understand is that CoD and that like are not the only form of shooters out there, which puts a huge injustice upon a genre that definitely is very good. Call of Duty is very much overrated, but not by adults. I've had conversations with both teenagers and adults about their primary games that they play. Although I heard a lot of adults say Call of Duty, I heard more teenagers say it. It seems like teenagers play more Call of Duty because they believe it will make them a "hardcore gamer" when in reality, just playing a single, overrated shooter does not make you a hardcore gamer. Adults however, have learned to have a larger variety of games. I wouldn't be surprised if most Call of Duty sales are from teenagers.
However, you neglect the fact that there is more than just a first-person shooter. You have your third-person shooters which are very different story wise and gameplay wise. Just take a moment and think about the similarities between Mafia II and Modern Warfare 3. What's the best thing you can come up with? They use guns? They curse? A lot of games use both. Heck, Red Steel 2 wasn't even primarily a shooter, but there are guns and cursing there. Red Steel 2 and Call of Duty have nothing in common. Dead Space 2 is another example, a third-person shooter/horror. They are so far from each other in any case, one side is a war, the other is escaping from an infected space ship. There are plenty of other examples, and I could easily go on.
But first-person shooters are rarely similar too. Battlefield, Call of Duty and Medal of Honor, yeah, they're similar, but because of the same setting; war. But look at Bioshock. Gameplay is entirely different, story is entirely different, characters are entirely different. There's almost no quality that Bioshock has that can be matched with Call of Duty. Calling First-Person Shooters all the same is a stereotype that really needs to be put to rest. I've played Call of Duty, I disliked it, but I moved on. You have to take into consideration that other people may like it, even though you don't. How many of your friends like Zelda? Cause so far my counter on mine is 0. First-Person Shooters are very different from games like Zelda, but just because one franchise isn't very good does not ever mean that the entire genre should suffer for it.