You're right. Mariah Carey might be the worst, although Celine Dion is certainly a qualifier (as is Babs Streisand). I'd rather scoop out my eardrums with a teaspoon than listen to any of that overwrought, self-indulgent crap, wherein the "artist" turns every single note into a scale or an arpeggio that seems to go on longer than did the Clinton Administration.
John Lee Hooker, OTOH, is "The Man". Buddy Guy is pretty good, too. Boom Boom.