Bad singers, good songs...

Kanye broke the cardinal rule of bad singing. He stepped outside of his preapproved vocal zone.
No one expects Kanye to sing. In fact, no one wants Kanye to sing, because we know he can't. Write an insanely catchy melody? Continue to be the biggest ego on the planet? These are the things we want from our Kanye. But when he begins to think he can pull off a ballad by actually singing it? That's when he's gone too far.

There are two kinds of bad singers in the world. The ones who kid themselves into thinking they're goodand the ones who try too hard, all the time. These are the Mariahs, Beyonces, and Christinas, although Ms. Aguilera is learning; her Nina Simone tribute on the Grammy nomination show this month was remarkably restrained. They wring the last bit of life out of every note. Just because you can sing every octave perceptible to the human ear doesn't mean you have to. These singers don't know when to hold back...
Other legendary bad singers: I'll avoid say - Yoko Ono and Michael Bolton. She inspired the B-52s. And Bolton has received his punishment for butchering so many songs by being relegated to "Where are they now?" Time has passed him by.
These peoples are ones who won't go away. And won't learn to sing.