Believe it or not, stuff like that used to really "whoosh!" on by overtop people's heads, especially when it came wrapped inside the received-wisdom-crap bonbon of a horror movie. Because horror couldn't possibly be about more than run-run, scream-scream, stab-stab, right?;)

However, I really don't think People Under the Stairs was ever actually conceived as a kids' movie. I think that's more a tribute to how our standards have shifted, especially vis-a-vis the MPAA ratings system; hell, The Exorcist is supposedly PG, these days. The last time I saw it in a theatre, people had brought toddlers...and babies.