If the guns in the war didn't shoot fast enough, there were always other solutions. You think the Battle of Gettsyburg would have been won by the north if the 20th Maine hadn't Chamberlain called a bayonet charge? Nah! I'd love to see Wiimote bayonet and rifle controls. There are a lot of possibilities to innovate in the genre.

And you're forgetting about Korea and the Gulf War. Both were, okay...in the eyes of the public.

The key selling points to shooters hardly have anything to do with the genre.  It has to do with the looks of the game.  Not graphical, but what's in it.  Do you know how many people would have bought Halo if you played as one of the human soldiers and not a spartan.  Well I know I wouldn't have bought it haha.  Also in the looks has to have a cool look of the gameplay.  Gears is an awesome example which further proves the stereotype.

Secondly the game has to have an online setup that says its different from the others, vouching some new gimmicky online component but otherwise the exact same.  Do this and with some decent hyping of gameplay elements that are that of the series and you got yourself a seller.  Cause in reality all people really want in a shooter, considering how simplistic and repetitive the gameplay is, is just an expansion pack to the ones they already like.  Because shooters are just so easy and unchallenging in single player, yet very appealing to a gamer, all they want is something that brings more of a challenge.  Thus you'll get games like Goldeneye 007 and Halo that show awesome multiplayer.  Then they want the next step so online with Halo 2 and then they want upgrades with new stuff.  Thus you get your run of the mill online shooters that give you the exact same things with new weapons, maps, online modes, and characters.  And that's it.  Your paying $60 for an expansion pack.  Got to hand it to the devs its pretty smart.  Unfortunately sooner or later the gamer will wise up and want more after repetitiveness gets old and that's when the market becomes oversaturated and the genre goes into a recession and given the popularity of it, possibly hurts the market as a whole.  Scary eh.

How painfully glib.

There are so many factors that make a shooter successful. If it was as simple as you suggest, then why do sooo many that fit your criteria fall through the cracks with mediocre sales?

What about controls? Sound? Draw distance? Hit detection? Physics? AI? None of that plays a role in how successful or well-received a shooter will be?

Shooters have plenty of room for imporvement and none of it is simply "incremental" or arbitrary. Entirely new engines are created to vastly improve all aspects of the genre. They are not merely expansions to an already perfected system.

America lost that war?? Maybe if you believe leftest communist lies then yes the US did lose the war. The US won well over 99% of the engagements and destroyed a country. I don't know how anyone can think they lost.