why is "bowl of soap" so popular when referring to the show? lol

Because I think it was the guy who plays Neal tweeted Robert 'You're a bowl of soup' and Robert respond 'You're a bigger bowl of soup' and then the whole cast pretty much started calling each other bowls of soup.

This site has links to some of the tweets; link

I was wondering that to

Bowl of soap? That's not very tasty. And they are not at all clean...

Oh, soup. It could be because the characters are all mixed up like soup. You have many different elements from fairytales that come together as one. I don't know who started it, and this is just a guess.