Suspension of disbelief?

I was reading an old post where someone was dismayed because of posters pointing out plot holes, dumb characters, dumb lines, stuff like that because we should have suspension of disbelief. I don't believe that's what it means. Suspension of disbelief to me is about accepting the premise of the fiction, things like disregarding that a play is people in costume on a stage reciting lines, that Harry Potter magic is real, that dinosaurs can be brought to life in Jurassic Park, that spaceships can travel faster than light, because those things are true within the universe of those movies. It isn't turning off your brain and ignoring common sense understanding of how the world or society works. For example in the movie Dark Waters (2003) they abandon ship ... on a submarine ... 5,000 feet deep. Nothing in that movie suggests people can survive at those depths so suspension of disbelief doesn't apply.