Morriseys great vocals came from his lyrics and flow, not his voice as such. He didn't have a great range, either in tune or passion.
Also, for those who have been singing Grace's praises for Jeff Buckleys vocals, check out Sketches For My Sweetheart My Drunk. It's got, IMHO, better singing than Grace.
Also, if this is the 22 best singers since 1983, I don't think Freddie Mercury should be that high. His reputation was built on his singing in the seventies. In the eighties, his vocals were hidden more behind slight distortion, and his range was much slighter.