Please forgive me if I’ve missed it, but I haven’t seen any mention of children in this thread.
Children should never be allowed to use any light without proper supervision. It’s amazing how many otherwise-sensible adults will give a powerful light to a child without a second thought.
Children will stare into the beam, shine it in other people’s faces, light up moving vehicles, mess about with the batteries and generally do everything they shouldn’t.
In addition, a child’s eyes are more delicate than an adult’s, because the cornea and lens become less transmissive (especially of bluer wavelengths) as people get older, and it’s the blue wavelengths that do the most photochemical damage to photoreceptors.
Blue light damage is especially significant when it comes to long-term, cumulative exposure over a lifetime. You don’t have to focus enough energy on the retina to do thermal damage; you can do photochemical damage at much lower intensities, and that damage can be much more insidious.
Finally, there’s a tendency for children and even some adults to push through mild discomfort - overriding their aversion response - in order to keep staring into a light source that fascinates them in some way. You have only to look at all the people who end up being treated for eye injuries after staring at the Sun during a solar eclipse for proof of that.