Well that's wrong.KhaineII said:...MW2 is supposed to be a realistic representation of warfare. Or, so it's developers would have us believe.
The developer even specifically said that they were going for more of a Hollywood, action movie feel, not realism. Call of Duty has never been about 'realism'. They use real-world guns, real world locations, and real-world politics (Sort of), but that certainly doesn't make the game realistic. At all.
But, more on topic, I agree with the 'fun' part. And as long as the game isn't 'realistic' or shooting for realism, then who cares? I loved the akimbo MOD for Quake 3. It was hilarious! Dual rail-guns, or dual rocket launchers just made the game that much more entertaining. Now, if it came up in Rainbow Six or Ghost Recon or some other game series that at least attempts some degree of realism, then I would see how that would be just silly. But if it's just a fun shooter, then dual-wield away! It's fun.