In reply to SMH.

Ya'll caping for Walter when all he does is contradict himself. This is what he said just two years before bitterness set it:

“The thing about Mariah is that she’s such a master melodist,” songwriter Walter Afanasieff told Billboard in 2016, reminiscing about working with Carey and Boyz II Men on “One Sweet Day.” “Today, that’s commonly referred to as a ‘top-line writer’…. someone who can start singing right off the bat. Mariah is such a gifted top-line writer that she can sing melodies and come up with lyric ideas on the spot

No one is claiming she does everything herself. Mariah has never claimed that she does either. Walter was a co-writer because he wrote the music to her early songs. Lyrics + Melody + Music =A song. Mariah is not an instrumentalist. So, she takes her melody ideas and fleshes them out further with someone that can actually write music.