It’s not easy to admit this, and depending on the company it can become downright impossible. It’s hard to explain to a non-Diamond-fan what you see in the stuff. It kind of reminds me of Metalocalypse actually: it’s something you make fun of, but it’s more funny because you actually do love it.
The fact is, you can’t listen to “Come To The Sabbath” and not know that Mercyful Fate is a completely sick band. Also consider that people like Danny Carey (Tool’s Drummer) grew up on and were inspired by them. So don’t dismiss them based on Diamond’s voice alone; this is some of the best metal ever.