It's easy to start believing single crew is safe because there's nobody to tell you when you're screwing up and don't know it.
300000 hours between 500 pilots is only 600 each, maybe the same as ten months hours flown at a medium airline,I'd hardly expect an accident in that time.
A well trained and motivated two crew cockpit is by far the safest option in my opinion.I also found that there are lots of people who think they know what that means but really don't IMO.
I flew single crew night freight on KingAirs for a year and saw two mates killed in seperate accidents in that short time. Flew a Lear for a while with no SOP's and that was just about as bad!