Halo and CoD are linear, but I don't know how you'd do a war based shooter without forcing you to go and follow a story. You can't make CoD into Fallout. They're linear because they're meant to be I mean, I'm sure they could add some larger options for exploration, but at the same time, you're supposed to be a soldier following orders. You go and do the job you're told to do. Straying from that in a military situation would slam you with tons of military judicial charges like going AWOL and dereliction of duty and whatnot.

As for the campaigns being short, I can't fault you on that.

You also have a point on the graphics. I'm not sure how updating graphics would screw with multiplayer framerates and supporting things like that. I honestly don't know.

I would say you're right with a lack of creativity, and that would be my biggest pet peeve, but so many games do the same exact thing.

Nintendo is notorious for that with Mario and Zelda, especially with the rehashing of old games with a minor tweak. Links Awakening, now in color! They're the same game, or same style (with the exception of Mario Sunshine and Wind Waker). Granted, I'll say that these games are very well made and are incredible productions. This is coming from someone who loves the games.

Soul Calibur is the same thing over and over. Add a few more characters and there ya go. Hell, I think that franchise has less replay value.

The Metroid games were the same thing with the exception of enemies and power ups.