Artists take riffs and melodies from other songs they like. Rock artists do it just as much as R&B folks do. Rappers do it more than anyone else obviously but that's what the music has always been based on. Rap was created from people rapping over other artists songs at parties so we can't be too surprised at what it is now.
If you want to believe in Alicia Keys again I suggest you listen to the tracks after "You Don't Know My Name." She totally produced and wrote both "If I Can't Have You" and "Diary" (which is the next single). The only other R&B artist that produces as much as Alicia is Tweet so you have to give her some cradit since there's so few artists that can do that. She didn't produce You Don't Know My Name so don't blame her for that.
Just FYI, very few rock and Jazz artists produce their own songs as well. Even Norah Jones, for as many grammies as she won, didn't really produce her own songs.
