A bit unkind this thread, or what?
So I won't name any names, tho' I can think of a few whose songs are spell-binding, great lyrics, even if they haven't got the greatest voices.
But I saw one last week, who writes great songs, sings in tune BUT has a horrible rasp in his voice that turns me right off: makes me want to clear his throat for him or tell him that as he's using a mike, he doesn't have to shout down it.
And just another (sexist?) observation: it's easier for men with not very good voices to get away with it than it is for women (being one myself)!