Because they actually remembered "Hey Jude"! It's the song that Dean and Sam's MOM sang to them!<<<I think the song O' Death by Jen Titsu or someone should be on there! That's Death's entrance song and I love it!
But can you imagine Moriarty running into Crowley? I mean, Moriarty is scary and psycho, but he's human. Crowley could destroy him with a snap of his fingers. Basically I'm saying I would love to see Moriarty shaking in his boots before Crowley 😈