9. Ozzy Osbourne and Ronnie James Dio
When you get kicked out of your band, you're always going to have mixed feelings about the people who wanted you gone. Even if you were in Ozzy Osbourne's position where you kind of deserved to be kicked out, you're not going to see if Tony Iommi wants to go to dinner anytime soon either. You think that's bad though? Wait until you hear the choice words that the Prince of Darkness had to say about his replacement.
Despite being a dramatic improvement on the raw execution front, Ronnie James Dio got a paddling from both Sabbath fans and Ozzy himself when he started. Before the Ozzman had even released a solo album, he was already badmouthing Ronnie to the press, saying that the band has no right calling themselves Black Sabbath without him. Once the lines were drawn though, things got a lot more nasty.
With Ozzy looking at the charts to see the position of his former bandmates' albums, he also got a little too disrespectful out on tour when he employed a dwarf to be at his beck and call just to be called Ronnie for the remainder of the tour. While Ronnie took it in stride, it did escalate to him declining to open up the first Ozzfest as Sabbath's singer since Ozzy was the headliner. Even though these guys look like badasses that emerged from Satan's spawn, there's an awful lot of insecurities on both of these fronts.