I feel like you're talking about the multiplayer characters, if so I'm with you. I could care less what my guy looks like. I don't look at myself in the mirror anyways when I'm playing CoD xD
Well, in WaW, you were introduced to Reznov by playing as Dimitri, and when Black Ops 1 came out, you played as Alex Mason and you were introduced again to Reznov from the prison. Then in Black Ops 2, you played as Alex Mason's son, David Mason. A lot of the character's origins and how they entered the series can be confusing sometimes.