In all fairness Makeithappencaptain, go through the ATSB and have a look at the number of Sport Aviation accidents, 18 Aircraft which resulted in Fatalities, resulting in 21 Fatalities from 2002 - 2011, 344 Incidents and 31 Serious Incidents, compared to lets say Aerial Work which has 41 Aircraft involved in Fatalities resulting in 56 Fatalities, 2,587 Incidents and 134 Serious Incidents.
Admittedly for the Sports Aviation it doesn't include Accidents/Incidents per Million Hours unlike the Aerial work category does so we can't get a really good comparison, but my point is that maybe you should rethink your statement. An AOC doesn't automatically make an operation safer, nor does the lack of one make it less safe than others. Percentage wise, I wouldn't be surprised if there were just as many dodgy AOC Holders operating as there are Skydiving Operators without an AOC.
I felt compelled to type this as someone who has operated at 2 different DZs (Not a large number admittedly) and don't appreciate the implication that the work I conducted was dodgy or unsafe.