Roxas was an umbrella term for Twilight Town and all things related to that subplot.
It was a good story in Days, but in KHII? It added nothing other than Sora going "Why do they keep calling me Roxas!??!" and giving Axel a reason to be renegade.
Nevermind that Chain of Memories was building Axel up to be a guy that may have started out just trying to help out Roxas, but ended up really liking the double-crossing and subversion for it's own sake.
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http://i498.photobucket.com/albums/rr345/Rakaputra/pjbasis.png
SuperNiceDog - 1, pjbasis - 0