I think where I came from was that -- mind control is very dark, yes, but arguably not as dark as Ianto doing it himself, voluntarily. At least to my mind. Nick actually said he wasn't interested in reading it because he didn't care for the idea that Ianto wasn't in control of his actions (he likes it better when Ianto's a lying liar who lies; I suspect it wasn't dark enough for him :D).

Though yeah, I can see how the rest of it would be. Though Jack has genuine fun on his days off! AS WE SHALL SEE. :D