They deserve to sell better than KZ2 because they are better games. For all the flack Halo 3 takes on forums, people seem to miss that the underlying game is a riot to play, especially multiplayer. Same with Gears, co-op mode is just plain fun, it's worth the price of admission just for that.
I think the insane forum hoopla surrounding KZ2 has skewed people sales expectations. If we are to believe the internet, then the only game that matters is KZ2, and the only game people will want to play is KZ2. As usual though the forums have little basis in reality. Simply put, there are just many games out there that are better than KZ2. Simple as that, no need to spin or skew it.
It does not have the best graphics out there. Yeah that's always controversial to say on the internet...but try an independent focus test and see where KZ2 falls, you may be surprised, or possibly shocked.
It does not have the best control. Why they chose to go with a controller stuck in cement feel is beyond me, but going against the grain in the fps world was an odd choice.
It does not have the best multiplayer. People will constany say "yeah but it's free", but so is a Ford Pinto. Multi player issues in an fps game just won't cut it today.
It does not have the best game play. The game brings nothing new to the table.
It does not have the best brand pedigree.
Hence, it's selling as expected. None of the above implies that the game is bad, but I can't see why people are shocked that it's not selling millions. To a certain extent I agree with Scott_Arm. Sure marketing helps, etc, but in the end it's selling exactly as much as the market deems it worthy of.
I guess that cinches it. Except we've been discussing this exact same thing with Scott for the last, what, 20 posts?