As the skydiving instructor, I didn't check everyone's equipment was functioning properly before jumping.
Are you joking? Why wouldn't you check your students' equipment?
Skydiving is not dangerous, if people are experienced.
Skydiving is dangerous and you need to make sure the equipment is right before people do it. It could literally be a difference between life and death.
It's fine. I just want to jump, not worry about my students.
It would be deadly if someone's equipment didn't work mid skydive. You should always be checking to make sure it's functioning correctly before jumping.