I agree that it can get a bit scary and I've definitely felt unsafe around inexperienced shooters at my range when it gets crowded.
My father taught me thoroughly the importance of safety with firearms at a young age and I've never forgotten. I'm sure most of us here have had a similar experience with our mentors.
While I don't like the insecurity of worrying about the guy next to me at the range, I feel we (experienced shooters) have a responsibility to at least try to teach others (even strangers) what we know. At least as far as safety is concerned. Seeing as some of those people at the range didn't have the same privilege of having a mentor teach them proper handling of firearms.
Just my $.02