It's usually a matter of marketability. A lot of those adaptions are intended for children so the gory details aren't really suitable.

( But she smiles pleasantly rather than seem like she's judging his opinion. Those who lean towards the darker sides of life aren't unknown to her. The creator she's spent her life with up until this point is hardly sunshine and rainbows.

But he never meant for her to look into the darkness. )

I don't think it really matters, quite honestly. From my experience so far, most seem to be... varied in their backgrounds.

( In other words, not to worry. Not that he sounds particularly bothered. Still, it's in her nature to offer reassurance. )