Alice is not iconic because video games are not that iconic, and, honestly? If a video game isn't that iconic, then a character from a mediocre video game spin-off certainly isn't. My all time favorite games outside of Batman are The Last of Us and Red Dead Redemption, yet, while I would argue that Joel and Ellie and John Marston are, indeed, iconic, within the confines of their particular medium, nobody in the General Public will ever be able to reconcile the popularity of a John Marston with that of, say, The Man With No Name...because video games, sad a story it is to say, are still very much a niche medium. You ask people what they think of when you say "popular video game characters," and nobody's gonna ****ing know who Altair or Kratos are. They'll probably say Mario or Pac-Man, or misattribute Link to being Zelda, as nostalgia has engrained those characters in the public consciousness and time has allowed them to thrive as faces of a brand, more than as game characters, themselves.
So, yeah, I'm with wez on this one. Alice isn't iconic. Resident Evil isn't iconic. Video games, for all intents and purposes, as they exist now: not iconic.
not even the Mary Sue Leon could've helped the game franchise. He's now a generic video character. And Selene wishes she was Alice. 
