Agreed, something I think folks need to realize is what constitutes as dark, disturbing and scary to someone is completely subjective.
What freaks someone out might not be the same as others, case in point while clowns can be downright terrifying for some, they're absolutely tame to everyone else. Now clearly, whatever treatment John Murdy was working on definitely disturbed him. But question is, what does he find disturbing? Horror is very much a broad genre, and it comes in many different forms. And as I've discovered time and time again, you don't need to be gory to be absolutely screwed up and/or downright scary.