Yeah well at least Ozzy(tm) made up for his lack of any tonal quality in his voice with his song writing ... I guess not. His stage presence , nope. He was a decent cool guy , a stand-up business guy who made honest deals and gave everyone a fair shake , um nope. And it's not that he isn't a great vocalist , he's a horrible vocalist and an awful person to go with the package man.
ALL. OF. THIS. I just made one little tweak to make it perfect.
I'm late to the party here; my pick is Maiden, but it's very very close.
As for the above, I think that's all overstating things to a large degree. I LIKE the way he sings on some of the mid-period Sabbath (I can't imagine anyone doing justice to "Spiral Architect" like Ozzy; listen to how Dio struggles with some of the Ozzy stuff live) so the tonal comment is totally subjective. And as for the rest, well, I guess you had to be there. There are a lot of people that know him a whole lot better than any of us that say quite different. After all the public nonsense and scuttlebutt, the only ones with a real hard-on for the guy are Daisley and Lee, and that's all about money. Iommi is reportedly still friends with him. Zakk Wylde LOVES the guy, worships him, basically.