Because then the game could become very imbalanced. The standard perks would have to be able to counter the DLC perks....the KS's would have to be able to be countered by standard weapons and such....etc....that is why the do not do that in a DLC. Also...could you imagine the rage that would follow for people that did not want to download this?

I think it would keep things fresh if they added weapons packs. It would not unbalance the game at all. Everyone uses different weapons as it is now. (You don't see everyone running around with a Scar right?) They could probably even sell one or as a set. It would be cool to see them bring back guns like the TAR, Steyr-Aug, Galil or new ones never before seen on COD.

Activision would make money, we'd be happy.

they cant fix game u wanna new guns !!!!

I would assume that they would not want to split up the player base any more than they already do with the map packs.

It would obviously be unbalanced to have some players having "better" weapons than others. You can argue that weapon choice is a mater of preference, but imagine if say the following were DLC only (Type 95, Striker, MP7, L118A, MG36) The only fair way to handle it would be to keep those with the DLC weapons separate from those without.

It already takes a long time to find a match with the DLC enabled (and it is rare when those games connect well) You basically have the following:

Those without DLC (obviously the majority of players)

Those with Elite Premium + those with DLC 1 and DLC 2 (I think the second largest group)

Those with DLC 1 only

Those with DLC 2 only

Keep in mind that as soon as they release more DLC the players with DLC 1 and DLC 2 will split off from the Premium members and become their own group.

Releasing weapon DLC would effectively double the number of groups. Unlike map DLC you couldn't just turn it off, and search for a group without it. You would have to change all your custom classes if you turned it off.

You are basically left with two options.

1 Fracture the player base even more, and make good connecting games become less frequent.

2 Make the people that don't have the DLC (the majority of players) feel that they are at an unfair advantage because they didn't buy the new weapons. This will likely cause them to stop playing the game.

Well they could pull it off acctually seeing as battlefield 3 can do it, But the guns had to be really balanced after the dlc because there were op. So thats why they dont probally do it. Honestly id love to at least see some new guns such as the tar-21 my favorite gun but i doubt it will ever happen.