You might be the only rational person in this thread. WaW had one new zombie map per pack with a total of three map packs, Black Ops 1 had one new zombie map per pack, with a total of four packs. The only reason the WaW maps were released was because they were included with Hardened and Prestige editions, a lot of games will release the content that was included with special editions as DLC. Black Ops 2 season pass was advertised as 4 DLC map packs total. So far, each pack has followed the same scheme, with one zombie map per pack. Nuketown zombies was released as a seperate purchase because it was initially part of the Hardened and Care Package editions.
Not only that, but Waw zombies and Black Ops 1 zombies were played on a modified version of the single player engine. Black Ops 2 zombies are played in the multiplayer engine. I imagine it would take a considerable amount of resources to port the old maps into the multiplayer engine.
And just for fun, here is their statement on what microtransactions mean for Black Ops2
"This content contains either personal customizations or nice little luxuries that I've seen players request; none of them affect game play, but they are small, specific ways to enhance your online experience," wrote Activision's social media manager Dan Amrich.