every shooter that finds its way to the XBox has to be like Halo. otherwise the hardcore Halo Fanboys that make up 70% of the XBox Shooter playerbase won't play it.
Halo is the holy grail and the gold standard of XBox shooters, and if your game isn't like Halo, then it is crap.
as someone who spent most of his time playing GRAW2 and Bad Company 1 on 360, and never really played Halo outside of finishing the campaign mode, i know this all to well.
Halo fanboys are like the borg. and they spend considerable effort to downtalk any and every upcoming shooter that isn't made by Bungie. just go take a look at any xbox forum for a non-Halo shooter.
Gears of War fanboys are the same, only not to the ridiculous extreme that Halo fanboys go.
I remember Halo fanboys on forums bashing Bioshock 1....just because it was a shooter and it wasn't Halo. even though Bioshock 1 had no multiplayer at all. those were the days of very frequent facepalms.