Why was Whitney Houston's 1990 album I'm Your Baby Tonight not as successful?

[Hawkee]

In my box of music I found my copy of Whitney Houston's 1990 album I'm Your Baby Tonight and I never have figured out why people called this album the weakest selling album of Whitney Houston. Was this album horribly received by critics or were people shocked at the new image and direction this album had taken for Whitney Houston? Because the way I see it in all honesty this album was heading Whitney into her R&B sound and the title song I'm Your Baby Tonight shows that Whitney Houston could mix rock and R&B music in a power song. But the most oddest thing I discovered on this album was that Whitney did a duet called We Didn't Know with Stevie Wonder and this duet is supposed to be a power ballad but this song isn't a ballad at all and I secretly think Whitney Houston wanted to record an album with Stevie Wonder but never had the chance to do it. I also heard that this album had an EP with a song called Taking A Chance and a cover of Higher Love too

[Hawkee]

I also learned that one of the songs on Whitney Houston's I'm Your Baby Tonight album called All The Man That I Need is actually a cover of a song by Linda Clifford but Sister Sledge covered it in the 80's. Did this Whitney Houston cover song become a single from I'm Your Baby Tonight?

[Dude111]

I dunno if I heard any of those songs Hawk but I love her 1985 album!!