Last night on American Idol, Mariah dismissed "Like a Prayer" as being "not a big singing song." Look, plenty of Madonna's songs, including indelible pop classics like "Into the Groove" or "Borderline," could fairly and objectively be classified outside the "big singing song" category. Not so with "Like a Prayer," which even without its big singing choral aspect has plenty of opportunity within its verses for belting (and which features one of Madonna's best vocal performances ever).
For Mariah Carey to sing a song, she almost always insists on oversinging it. Give her "For He's a Jolly Good Fellow" and "fellow" would have 18.5 syllables.